acid
1 of 2noun
ˈa-səd 
1
: a sour substance
specifically : any of various typically water-soluble and sour compounds that in solution are capable of reacting with a base (see base entry 1 sense 6a) to form a salt, redden litmus, and have a pH less than 7, that are hydrogen-containing molecules or ions able to give up a proton to a base, or that are substances able to accept an unshared pair of electrons from a base
2
: something incisive, biting, or sarcastic
a social satire dripping with acid
3
: lsd
acidy adjective
ˈa-sə-dē
acid
2 of 2adjective
1
a
: sour, sharp, or biting to the taste
an acid flavor
b
: sharp, biting, or sour in manner, disposition, or nature
an acid individual
an acid personality
c
: sharply clear, discerning, or pointed
an acid wit
acid criticism
d
: piercingly intense and often jarring
acid yellow
2
a
: of, relating to, or being an acid
also : having the reactions or characteristics of an acid
acid soil
an acid solution
b
of salts and esters : derived by partial exchange of replaceable hydrogen
acid sodium carbonate NaHCO3
c
: containing or involving the use of an acid (as in manufacture)
an acid bath
d
: marked by or resulting from an abnormally high concentration of acid
acid indigestion
3
: relating to or made by a process in which the furnace is lined with acidic material and an acidic slag is used
acid steel
4
: rich in silica
acid rocks
acidly adverb
acidness noun
Synonyms
Adjective
- acidic
- acidulous
- sour
- sourish
- tart
- tartish
- vinegary
See all Synonyms & Antonyms 
Example Sentences
Noun the acids in your stomach the kinds of acid found in your stomach Adjective He washes his windows with an acid solution of vinegar and water. with her acid personality, my aunt could be relied upon to bring some much-needed balance to the holiday gush
Recent Examples on the Web
Cesar Hernandez, San Francisco Chronicle, 6 Sep. 2022 When left in a device for a long time, batteries will continue to slowly discharge, and a build-up of gas will leak out in the form of battery acid. Joe Difazio, USA TODAY, 25 Aug. 2022 Season with salt and pepper, and for an extra flourish, finish with a bit of acid, such as lemon juice or vinegar. Becky Krystal, Washington Post, 22 Aug. 2022 And raw shallots, mellowed out by a stint in vinegar, make this such a fun, punchy condiment to add to any protein or veggie that needs a hit of acid. The Bon Appétit Staff & Contributors, Bon Appétit, 5 Aug. 2022 For every pound of yogurt, three to four pounds of acid whey are produced, which unlike sweet cheese whey, cannot be used in protein powders. Rebecca Cairns, CNN, 29 Mar. 2022 The facts seem to bear that out: As a 4-year-old living in Brooklyn in 1973, he was severely burned and left blind after a mentally ill neighbor poured a bottle of acid over his head. Eileen Finan, PEOPLE.com, 11 Feb. 2022 These drugs, especially intravenous zoledronic acid (and the antibody to RANK ligand, denosumab), have been game-changers in patients with breast and other cancers that spread to bone. Dr. Keith Roach, oregonlive, 9 Aug. 2022 Perhaps one of the most concerning chemicals, though, is perfluorooctanoic acid (or PFOA). Joshua Hawkins, BGR, 9 Aug. 2022 Grace Wu, Good Housekeeping, 4 Aug. 2022 Granites may contain trace levels of acid-sensitive minerals, so don't use cleaning products containing lemon, vinegar, or other acids. Caitlin Sole, Better Homes & Gardens, 4 Aug. 2022 Many of the names are familiar: the lime green lace gown is by Alaïa, remade in an acid tone from runway orange. Rachel Tashjian, Harper's BAZAAR, 3 Aug. 2022 Robinson is no stranger to epiphany; many of his earliest Sierra outings included an acid trip along the way. Verlyn Klinkenborg, The Atlantic, 21 July 2022 This can make the beverage an alternative for those with acid reflux or indigestion issues. Olivia Munson, USA TODAY, 29 June 2022 For all his gentility, Mr. Freed could be acid in his observations. Washington Post, 6 Jan. 2022 The painting was also damaged in an acid attack in the 1950s, according to the AP. Alison Fox, Travel + Leisure, 31 May 2022 It was also damaged in an acid attack perpetrated by a vandal in the 1950s, and has since been kept behind glass. Chron, 30 May 2022 See More
Noun
Same goes for the vinegar, which adds a fitting amount of brightness without driving the car into a pool of acid. Cesar Hernandez, San Francisco Chronicle, 6 Sep. 2022 When left in a device for a long time, batteries will continue to slowly discharge, and a build-up of gas will leak out in the form of battery acid. Joe Difazio, USA TODAY, 25 Aug. 2022 Season with salt and pepper, and for an extra flourish, finish with a bit of acid, such as lemon juice or vinegar. Becky Krystal, Washington Post, 22 Aug. 2022 And raw shallots, mellowed out by a stint in vinegar, make this such a fun, punchy condiment to add to any protein or veggie that needs a hit of acid. The Bon Appétit Staff & Contributors, Bon Appétit, 5 Aug. 2022 For every pound of yogurt, three to four pounds of acid whey are produced, which unlike sweet cheese whey, cannot be used in protein powders. Rebecca Cairns, CNN, 29 Mar. 2022 The facts seem to bear that out: As a 4-year-old living in Brooklyn in 1973, he was severely burned and left blind after a mentally ill neighbor poured a bottle of acid over his head. Eileen Finan, PEOPLE.com, 11 Feb. 2022 These drugs, especially intravenous zoledronic acid (and the antibody to RANK ligand, denosumab), have been game-changers in patients with breast and other cancers that spread to bone. Dr. Keith Roach, oregonlive, 9 Aug. 2022 Perhaps one of the most concerning chemicals, though, is perfluorooctanoic acid (or PFOA). Joshua Hawkins, BGR, 9 Aug. 2022 Adjective
Adjustable bases can be an expensive investment but offer incredible personalized comfort, especially for older users or those who suffer from acid reflux. Grace Wu, Good Housekeeping, 4 Aug. 2022 Granites may contain trace levels of acid-sensitive minerals, so don't use cleaning products containing lemon, vinegar, or other acids. Caitlin Sole, Better Homes & Gardens, 4 Aug. 2022 Many of the names are familiar: the lime green lace gown is by Alaïa, remade in an acid tone from runway orange. Rachel Tashjian, Harper's BAZAAR, 3 Aug. 2022 Robinson is no stranger to epiphany; many of his earliest Sierra outings included an acid trip along the way. Verlyn Klinkenborg, The Atlantic, 21 July 2022 This can make the beverage an alternative for those with acid reflux or indigestion issues. Olivia Munson, USA TODAY, 29 June 2022 For all his gentility, Mr. Freed could be acid in his observations. Washington Post, 6 Jan. 2022 The painting was also damaged in an acid attack in the 1950s, according to the AP. Alison Fox, Travel + Leisure, 31 May 2022 It was also damaged in an acid attack perpetrated by a vandal in the 1950s, and has since been kept behind glass. Chron, 30 May 2022 See More Word History
Etymology
Noun
borrowed from Medieval Latin acidum, going back to Latin, neuter of acidus acid entry 2
Adjective
borrowed from French & Latin; French acide, going back to Middle French, borrowed from Latin acidus, adjective derivative from the base of acēre "to be sour" — more at acetic acid
First Known Use
Noun
1650, in the meaning defined at sense 1
Adjective
1649, in the meaning defined at sense 1a
Phrases Containing acid
Kids Definition
acid 1 of 2
adjective
ac·id ˈa-səd
1
: having a taste that is sour, bitter, or stinging
2
: harsh or critical in tone
acid remarks
3
: of, relating to, or like an acid
an acid solution
acid
2 of 2noun
: a chemical compound that tastes sour and forms a water solution which turns blue litmus paper red
Medical Definition
acid 1 of 2
adjective
ac·id ˈas-əd
1
: sour, sharp, or biting to the taste
2
a
: of, relating to, or being an acid
also : having the reactions or characteristics of an acid
an acid solution
b
of salts and esters : derived by partial exchange of replaceable hydrogen
acid sodium carbonate NaHCO3
c
: marked by or resulting from an abnormally high concentration of acid
acid indigestion
—not used technically acid
2 of 2noun
1
: a sour substance
specifically : any of various typically water-soluble and sour compounds that in solution are capable of reacting with a base to form a salt, that redden litmus, that have a pH less than 7, and that are hydrogen-containing molecules or ions able to give up a proton to a base or are substances able to accept an unshared pair of electrons from a base
2
: lsd
acid
adjective
1
as in acidic
causing or characterized by the one of the four basic taste sensations that is produced chiefly by acids an acid-tasting medicine Synonyms & Similar Words
Relevance
- acidic
- sour
- acidulous
- vinegary
- tart
- dry
- soured
- sourish
- tartish
- tangy
- unsweetened
- zesty
- pungent
- astringent
- zingy
- zestful
- puckery
- hyperacid
- sharp
Antonyms & Near Antonyms
- sweet
- smooth
- bland
- flat
- insipid
- tasteless
- watery
- dilute
- flavorless
- weak
- thin
- zestless
- savorless
2
as in bilious
having or showing a habitually bad temper with her acid personality, my aunt could be relied upon to bring some much-needed balance to the holiday gush Synonyms & Similar Words
- bilious
- angry
- irritable
- dyspeptic
- splenetic
- disagreeable
- ornery
- peppery
- cantankerous
- surly
- ill-humored
- exasperated
- indignant
- mad
- ill-natured
- ill-tempered
- bloody-minded
- upset
- choleric
- bearish
- petulant
- depressed
- anal
- snappish
- uptight
- irascible
- grouchy
- querulous
- irate
- crotchety
- contentious
- testy
- peevish
- crabby
- grumpy
- morose
- sullen
- dour
- cussed
- touchy
- short-tempered
- fussy
- contrary
- quick-tempered
- cranky
- glum
- snippy
- argumentative
- schoolmarmish
- old-maidish
Antonyms & Near Antonyms
- pleasant
- sweet
- amiable
- gentle
- friendly
- agreeable
- congenial
- kind
- effervescent
- benign
- content
- amicable
- bubbly
- exuberant
- nice
- joyful
- cheerful
- good-humored
- good-natured
- lively
- lighthearted
- vivacious
- cheery
- calm
- happy
- placid
- good-tempered
- serene
- glad
- tolerant
- patient
- high-spirited
- long-suffering
3
as in sarcastic
marked by the use of wit that is intended to cause hurt feelings a cultural gadfly known for an acid tongue that spares no one Synonyms & Similar Words
- acidic
- sarcastic
- satiric
- satirical
- corrosive
- barbed
- caustic
- acidulous
- acrid
- biting
- mordant
- acerbic
- tart
- scalding
- pungent
- sardonic
- cutting
- acerb
- scathing
- sharp
- snarky
- ironic
- cynical
- sour
- harsh
- dry
- smart-alecky
- smart-aleck
- cross
- smart-mouthed
- spiky
- blunt
- concise
- incisive
- ironical
- severe
- brisk
- trenchant
- sourish
- wry
- vitriolic
- poignant
- flippant
- facetious
- tartish
- acrimonious
- spikey
- bitter
- stringent
- abrupt
- keen
- gruff
- sharp-tongued
- resentful
- crisp
- pithy
- curt
- succinct
- brusque
- terse
- tongue-in-cheek
- backhanded
- insincere
- rough
- snippy
- brusk
- snippety
Antonyms & Near Antonyms
- mild
- playful
- amusing
- gentle
- merry
- sportive
- bland
- waggish
- droll
- smooth
- diplomatic
- suave
- urbane
- polite
- cordial
- genial
- good-humored
- good-natured
- hospitable
- affable
- sociable
- gracious