add-onˈadd-on noun [countable] 
Examples
We bought legal protection as an add-on to our home insurance policy.2a piece of equipment that you connect to a computer to improve its performance: an add-on circuit board3a product that is designed to be used with another product
ExamplesEXAMPLES FROM OTHER DICTIONARIES
Thesaurus- Add-ons such as modems and DVD drives can easily cost you hundreds of dollars.
- The Senate's add-ons to the proposed budget are likely to cause controversy.
- But in terms of add-on cost the calculation is simple.
- But over the years some had gained screened porches and various add-ons.
- For users, they are still expensive add-on features and come with their own set of integration problems.
- Instructional changes were limited and uneven, and educators largely viewed the program as an add-on.
- The present pattern of' add-on development will continue.
Longman Language Activatorsomething that is added► addition
1something extra that is added to an existing plan, agreement, law etcadd-on to · Additions are made to the list from time to time.addition to · There has been a last minute addition to the programme for the President's visit.a new addition (=a new person or thing in a group or list) · In the last three months there has been a new addition to the family - our daughter, Rachel.
► additive something added to food in order to make it last longer, taste better, or look more attractive: · This product contains no artificial additives.· Foods sold under this label are guaranteed to be free from additives and preservatives.
► supplement something that is added to something else in order to improve it or make it complete: · Doctors believe that vitamin supplements are largely unnecessary.supplement to: · He sometimes eats fish as a supplement to his vegetarian diet.· The current supplement to the encyclopedia 'Growing Up with Science' has a new section on cycles in nature.
► extra something which is added to a basic product or service which improves it and also costs more: · A wide range of extras are also available.optional extra British: · Tinted windows and a sunroof are optional extras.
► add-on as a piece of equipment that can be added or connected to a computer, car etc to make it do more things or make it more useful: · Add-ons such as modems and DVD drives can easily cost you hundreds of dollars.
► extension also addition American another room or rooms that are added to a building: · The Simpsons built a big addition onto the back of their house.· You'll find the Picasso collection in the extension to the museum.
WORD SETS► Computersaccess, verbaccess point, nounaccess time, nounaccounting system, accumulator, nounadd-on, nounADSL, nounaffective computing, nounAI, nounALGOL, nounalias, nounANSI, anti-spam, adjectiveanti-virus, adjectiveanti-virus software, nounAPL, nounapp, nounApple, Apple Macintosh, applet, nounapplication, nounapplication software, nounarcade game, nounarchitecture, nounarchive, nounarchive, verbarray, nounartificial intelligence, nounASCII, nounASIC, nounASP, nounassembly language, nounasynchronous, adjectiveAT&T, attachment, nounaudit trail, nounautomate, verbautomated, adjectiveautomation, nounavatar, nounB2B exchange, nounB2C, adjectiveB2E, adjectiveBabbage, Charles, backslash, nounbackspace, nounbackup, nounback-up copy, bandwidth, nounbar code, nounBASIC, nounbatch, nounbatch processing, nounbaud rate, nounBerners-Lee, Tim, bespoke, adjectivebeta test, nounBig Blue, bioinformatics, nounbiometric, adjectivebit, nounbitmap, nounBlackBerry, nounbloatware, nounblog, nounBluetooth, nounBMP, nounbond certificate, book entry, bookmark, nounbookmark, verbbook of final entry, nounbook of first entry, nounBoolean, adjectiveboot, verbbootable, adjectivebootstrapping, nounbot, nounbotnet, nounbps, brain dump, nounbroadband, nounbrown goods, nounbrowse, verbbrowser, nounbubble jet printer, nounbuddy list, nounbuffer, nounbuffer, verbbug, nounbulletin board, nounbundle, nounbundle, verbburn, verbbus, nounbusiness continuity services, nounbusiness continuity services, button, nounbyte, nounCabinet Office Briefing Rooms, cable modem, nouncache, nouncache, verbCAD, nounCAD/CAM, nounCAL, nounCalifornia, nounCALL, nounCAM, nounCambridge, Capita, caps lock, nouncapture, verbcapture, nouncard, nouncathode ray tube, nounCAT scan, nounCBT, nounCD-R, nounCD-ROM, nounCD-ROM drive, CDRW, nounCD-RW, nouncentral processing unit, nouncentral processor, nounCGI, nounCHAPS, character, nounchat room, nouncheat, nouncheckbox, nounchip, nounchip card, CIM, CIO, clerical assistant, click, verbclickable, adjectiveclient, nounclient machine, client-server, adjectiveclient/server architecture, clip art, nounclipboard, nouncloaking, nounclock cycle, nounclock speed, nounclone, nouncluster, nounCOBOL, nouncode, nouncoder, nouncom, Comdex, nouncommand, nouncomm port, comms, nouncompact disc, nounCompaq, compatibility, nouncompatible, adjectivecompatible, nouncompile, verbcompiler, nouncompress, verbcomputer, nouncomputer (industry) analyst, computer-aided, adjectivecomputer-aided design, nouncomputer-aided manufacture, computer-aided manufacturing, nouncomputer-assisted, adjectivecomputerate, adjectivecomputer-based training, computer-generated, adjectivecomputer-integrated manufacture, computerize, verbcomputer-literate, adjectivecomputer modelling, nouncomputer science, nouncomputer system, computer virus, nouncomputing, nounconcordance, nounconfiguration, nounconfigure, verbconnect, verbconnectivity, nounconsole, nouncontrol, nouncontrol key, nouncookie, nouncoordinate, nounCorel, corrupt, verbcounter, nouncourseware, nounCPU, nouncrack, verbcrack, nouncracker, nouncrash, verbcrash, nounCroft, Lara, cross-platform, adjectivecross-posting, nounCtrl, nouncursor, nouncut, verbcutover, nouncyber-, prefixcybercrime, nouncybernetics, nouncyberpunk, nouncybersickness, nouncyberspace, nouncyberterrorist, nouncyberwidow, noundata, noundata bank, noundatabase, noundatabase management, database management system, data capture, noundata centre, data dictionary, noundata encryption standard, noundata file, data interchange format file, data mining, noundata processing, noundata protection, Data Protection Act, the, Dateline, daytrader, nounday trading, nounDBMS, debug, verbdecision support system, decode, verbdecompress, verbdecrypt, verbdefault, noundefragment, verbDel, noundelete, verbdeletion, noundeliverable, noundematerialize, verbdemo, verbdemonstration version, denial of service attack, noundeselect, verbdesktop, noundesktop computer, noundesktop publishing, noundestination site, dialogue box, noundial-up, adjectivedigerati, noundigicam, noundigital nervous system, digital rights management, digital wallet, nounDilbert, direct access, noundirectory, noundisaster recovery, noundisc, noundisinfect, verbdisk, noundisk drive, noundiskette, noundisk operating system, display, noundisplay, verbdistributed processing, Dixons, dock, noundock, verbdocking station, noundocument, noundocument sharing, noundongle, nounDOS, noundot-matrix printer, noundouble click, verbdouble-click, verbdouble density, adjectivedown, adverbdownload, verbdownload, noundownloadable, adjectivedowntime, noundown time, downwardly compatible, adjectiveDP, noundrag, verbdrive, noun-driven, suffixdriver, noundropdown, noundrop down, noundrop-down menu, nounDTP, noundumb terminal, dump, verbdump, nounDVD, nounDVD-ROM, nounEasdaq, noune-book, noune-business, nounECN, noune-commerce, nouneditor, nounedutainment, noune-fatigue, nounE-FIT, nounEFTPOS, nounelectronic, adjectiveelectronic bill of lading, electronic cottage, nounelectronic data interchange, nounelectronic funds transfer, nounelectronic invoice, electronic mail, nounelectronic media, electronic publishing, nounelectronics, nounelectrosmog, nounEllison, Larry, email, nounemail account, embed, verbencrypt, verbend-to-end, adjectiveenter, verbenterprise application integration, nounentry, nounEPROM, noune-publishing, nounequipment leasing, erase, verbErnie, error, nounerror message, nounescape key, Ethernet, noune-ticket, nounE-ticket, nounexecutable, nounexecute, verbexecution, nounexit, verbexpansion card, nounexpansion slot, nounexpert system, nounexport, verbextension, nounextranet, nouneye scan, nounF2F, adjectivefabricator, nounfactory preset, nounfatware, nounfeed, verbfeed, nounfield, nounfifth generation computer, file, nounfile manager, nounfilename, nounfile sharing, nounfile transfer, filing system, filter, nounfirewall, nounfirmware, nounfirst generation, nounfirst in, first out, nounfirst-person shooter, nounfive nines, nounfixed wireless, nounflash, verbflash, nounflash drive, nounflash memory, nounflatscreen, adjectiveflat screen, flip chip, nounfloor broker, floppy disk, nounfly-by-wire, nounfolder, nounfont, nounfooter, nounfootprint, nounforklift upgrade, nounformat, verbFortran, nounforum, noun404, adjectivefreeware, nounftp, nounfunction, nounfunctionality, nounfunction key, nounfungible, adjectivefuzzy logic, nounGame Boy, gameplay, noungamer, noungaming, noungarbage in, garbage out, Gates, Bill, gateway, nounghost, nounGIF, noungigabit, noungigabyte, nounGIGO, GIS, nounGlitter, Gary, global, adjectiveGLOBEX, nounGMS, nounGoogle, gopher, noungraphical, adjectivegraphical user interface, noungraphics, noungraphics card, noungraphic software, grid computing, noungroupware, nounGUI, nounhack, verbhack, nounhacker, nounhacktivist, nounhandshake, nounhard copy, nounhard disk, nounhard drive, nounhardware, nounhard-wired, adjectiveHawk, Tony, Hawking, Stephen, head, nounheader, nounhelp, nounhelp desk, nounhelp menu, help screen, nounHewlett Packard, hexadecimal, adjectivehigh-definition, adjectivehigh-level, adjectivehigh-level language, highlight, verbhome computer, home office, nounhome shopping, hookup, nounhook-up, nounhost computer, hot key, nounhot link, nounhot spot, nounHTML, nounhttp, hyperlink, nounhypertext, nounIBM, icon, nounICT, nounidentifier, nouniMac, nounimport, verbinbox, nounincremental backup, nounincubator space, industrial design, infect, verbinfected, adjectiveinformation exchange, information retrieval, nouninformation system, information technology, nouninfowar, nouninitialize, verbinkjet printer, nouninput, nouninput, verbinput/output, adjectiveinstall, verbinstaller, nounInstinet, Intel, intelligent terminal, interactive, adjectiveinteractive whiteboard, nouninterface, nouninterface, verbInternational Securities Exchange, nounInternet cafe, nounInternet Service Provider, interpreter, nounintranet, nouninvoke, verbIP address, nouniPod, nouniris scan, nounISDN, nounISP, nounIT, nouniterate, verbiTunes, iTV, nounJava, nounjob, nounjob bank, Jobs, Steve, joystick, nounJPEG, nounK, KB, keno, nounkey, nounkeyboard, nounkeyboard, verbkeyboarder, nounkeypad, nounkeystroke, nounkeyword, nounkilobyte, nounkit, nounkludge, nounknowledge base, Kraftwerk, LAN, nounlanguage, nounlaptop, nounlaser disk, nounlaser printer, nounlaunch, verbLCD, nounlight industry, nounlight pen, nounline printer, nounlink, verbLinux, nounLISP, nounlisting paper, listserv, nounload, verblocal area network, nounlog file, LOGO, nounloop, nounlow-level, adjectiveMac, nounmachine, nounmachine code, nounmachine language, machine-readable, adjectiveMacintosh, nounmacro, nounmagnetic disk, nounmagnetic media, nounmagnetic tape, nounmail, nounmail, verbmailbomb, nounmailbox, nounmailing list, nounmail merge, nounmainframe, nounmainframe computer, main memory, manual, adjectivemaximize, verbmegabyte, nounmemory, nounmemory address, memory bank, nounmemory card, nounmemory hog, nounMemory Stick, nounmenu, nounmessage, nounmetadata, nounmicro, nounmicrochip, nounmicrocomputer, nounmicroelectronics, nounmicroprocessor, nounMicrosoft, MIDI, nounmigrate, verbmigration, nounMillennium bug, minicomputer, nounminimize, verbmips, mission-critical, adjectiveMIT, mixer, nounmodel, nounmodel, verbmodelling, nounmodem, nounmodule, nounmonitor, nounMoore, Gordon, Moore's Law, nounmorphing, nounmotherboard, nounMotorola, mouse, nounmouse mat, nounmouse miles, nounmouse potato, nounMP3 player, nounMP4 player, nounMPEG, nounMSC, nounMS-DOS, multimedia, adjectivemulti-player gaming, nounmultiple applications, multiplexer, nounmultitasking, nounnagware, nounNasdaq, nounNASDAQ, Naseem, Prince, National Market System, nounNEC, nerd, nounnest, verbNetscape Navigator, network, nounnetwork, verbneural computer, nounneural network, nounneuroinformatics, nounnewbie, nounnew economy, nounNintendo, node, nounnoise, nounnotebook, nounnumber-cruncher, nounnumber crunching, nounobject, nounobject language, object-oriented, adjectiveOCR, nounOfex, nounoffice machinery, offline, adverboff-line, adjectiveonline, adjectiveonline catalogue, online updating, nounon-screen, adjectiveopen, verbOpen Group, the, open outcry, nounopen system, nounoperating system, nounoperation, nounoptical character recognition, nounoptical fibre, nounoption, nounorder, nounorganizing business, OSI, nounoutbox, nounoutput, nounoutput, verbover-the-counter dealing, over-the-counter market, over-the-counter share, over-the-counter stock, over-the-counter trading, overwrite, verbP2P, adjectivepackage, nounpacket, nounpacket-switching, nounpage, nounpage break, nounpalette, nounpalm phone, nounpalmtop, nounpaperless, adjectiveparallel data query, parallel port, parallel processing, nounPASCAL, nounpass-along, adjectivepassword, nounpaste, verbpasting, nounpatch, nounpause, verbPC, nounPC Card, nounPDA, nounPDF, nounPDF file, pen drive, nounPentium, peripheral, adjectiveperipheral, nounpersonal communicator, nounpersonal computer, nounpersonal electronic device, nounpersonal organizer, nounpetaflop, nounphishing, nounping, verbpiracy, nounpirate, verbpixel, nounplasma screen, nounplatform, nounplatform game, nounPlayStation, plotter, nounplug and play, nounplug-and-play, adjectiveplug-in, nounpointer, nounpop-under, nounpop-up, nounport, nounport, verbportable, adjectivepost, verbpost-industrial, adjectivePostScript, nounPowerPoint, nounprint, verbprinter, nounprintout, nounprint-out, nounprint preview, nounprocess, verbprocessing, nounprocessor, nounprogram, nounprogram, verbprogram file, programmable, adjectiveprogrammer, nounprogramme trading, programming, nounprogramming language, PROLOG, nounPROM, nounprompt, verbprompt, nounprotocol, nounPsion, pull down, nounpull-down, adjectivepull-down menu, nounpunched card, nounquantum computer, nounQuarkXPress, queue, nounqwerty, adjectiveRAM, nounrandom access memory, nounread, verbread only memory, read-only memory, nounread-out, nounread-write, adjectivereal-time, adjectivereboot, verbrecall, verbre-chip, verbrecord, nounrecord, verbrefresh, verbreload, verbremaster, verbremote access, nounremote control, nounremote working, nounreseller, nounreset, verbrespawn, verbretinal scanner, nounretrieval, nounretrieve, verbretry, verbreturn, nounright-click, verbrip, verbroad warrior, nounrobot, nounrollover, nounROM, nounRoute 128, nounrouter, nounroutine, nounRSI, nounRTF, nounrun, verbsalami slicing, nounSamsung, save, verbscalability, nounscalable, adjectivescan, verbscanner, nounscramble, verbscreen, nounscreen-based, adjectivescreen dump, nounscreensaver, nounscreen saver, nounscreenshot, nounscroll, verbscroll bar, nounscroll key, SCSI, nounSEAQ, search, nounsearch, verbsearchable, adjectivesearch engine, nounSEATS, nounsecurity rating, SEGA, self-healing, adjectivesend, verbserial port, server, nounserver farm, nounservice bureau, nounservice pack, nounSET, nounset-up, nounSFA, nounSGML, nounshareware, nounshift, nounshift key, nounshoot-'em-up, nounshopping bot, sig file, nounsilicon, nounsilicon chip, nounSilicon Fen, nounSilicon Glen, Silicon Valley, sim, nounSIMM, nounsimulation, nounSinclair, Sir Clive, single sourcing, skin, nounslo-mo, adjectivesmall office/home office, nounsmart, adjectivesmart bomb, nounsneakernet, nounsoft copy, nounsoftware, nounsoftware engineering, SoHo, SOHO, nounSonic the Hedgehog, sort, nounsoundcard, nounsource code, nounspace bar, nounspam, nounspeech recognition, nounspeech recognition software, speech synthesizer, nounspellcheck, nounspellchecker, nounspell-checker, nounspider, nounspider food, nounspim, nounsplit screen, nounspreadsheet, nounspreadsheet software, spyware, nounstandalone, adjectivestand-alone, adjectivestandby time, nounStarr Report, the, nounstarter pack, nounstart-up, nounstorage, nounstorage unit, store, verbstore-and-forward, nounstrategic information system, stream, verbstreaming, nounStreet Fighter, string, nounstylus, nounsubdirectory, nounsubroutine, nounsuite, nounSun Microsystems, sunrise industry, nounsupercomputer, nounsuperserver, nounsupport, verbsupport, nounswitching, nounsynchronous, adjectivesyntax, nounsynthespian, nounsystem, nounsystem administrator, nounsystems analyst, nounsystems programmer, system tray, nountab, verbtab key, nountab stop, nountag, nountag, verbtape, nountape drive, taskbar, nountechie, nountechnical support, nountechno-, prefixtechnocracy, nountechno-geek, nountechnophobe, nountechy, telecentre, nountelecommuter, nountelematics, nounteleprinter, nounteleworker, nountemplate, nounterabyte, nounteraflop, nounterminal, nountestdeck, nountext-to-speech, adjectivethird-generation, adjectivethird-party software, thumbnail, nountickbox, nountick box, nountime out, nountime-sharing, nountitle bar, nountoggle, nountoner, nountoolbar, nountoolbox, nounTOPIC, nountop-level domain, nountop ranking, nounTorvalds, Linus, Toshiba, Tottenham Court Road, touchpad, nountouch screen, nountrackball, nountransaction processing, transputer, nounTrojan horse, nountroubleshooter, nounTTS, Turing, Alan, tutorial, nounundo, verbuninstall, verbunique visitor, nounUnix, noununlisted share, unlisted stock, unrecoverable error, unzip, verbup, adverbupdate, nounupgrade, verbupload, verbupload, nounuptime, nounusability, nounUSB, nounUSB drive, nounuser-friendly, adjectiveuser group, nounuser interface, nounuser name, nounUS Robotics, utility, nounVActor, nounvalid, adjectivevalue-added reseller, vapourware, nounVDT, nounVDU, nounVGA, nounvideocard, nounvideo game, nounvideo snacking, nounviral marketing, nounvirtual, adjectivevirtual corporation, virtually, adverbvirtual memory, nounvirtual office, nounvirtual organization, virtual reality, nounvirus, nounvoice print, nounvoice recognition, wallpaper, nounWAN, nounWAP, noun-ware, suffixwar game, nounWAV, nounwearable, nounWeb 2.0, nounweb browser, nounweb crawler, nounweb design, nounweb development, web-enabled, adjectiveweb hosting, nounweb log, nounweb log file, wide area network, wi-fi, nounWi-Fi, nounwild card, nounwindow, nounWindows, Wintel, wipe, verbWiponet, nounwireless internet, wireless networking, nounWord, Wordperfect, word processor, nounworkspace, nounworkstation, nounWorld Wide Web, the, worm, nounWozniak, Steve, write, verbwrite-protected, adjectiveWYSIWYG, nounXbox, XML, nounY2K, nounYahoo!, zap, verbzip file, nounzombie, noun
We bought legal protection as an add-on to our home insurance policy.2a piece of equipment that you connect to a computer to improve its performance: an add-on circuit board3a product that is designed to be used with another product