Word forms: plural, 3rd person singular presenttense rats, present participle ratting, past tense, past participle ratted
1. countable noun
A rat is an animal which has a long tail and looks like a large mouse.
This was demonstrated in a laboratory experiment with rats.
...a rat-infested derelict building.
2. countable noun
If you call someone a rat, you mean that you are angry with them or dislike them, often because they have cheated you or betrayed you.
[informal, disapproval]
What did you do with the gun you took from that little rat Turner?
Synonyms: rogue, scoundrel [old-fashioned], heel [slang], cad [old-fashioned, informal, British] More Synonyms of rat
3. verb
If someone rats on you, they tell someone in authority about things that you have done, especially bad things.
[informal]
They were accused of encouraging children to rat on their parents. [VERB + on]
4. verb
If someone rats on an agreement, they do not do what they said they would do.
[informal]
She claims he ratted on their deal. [VERB + on]
5.
See to smell a rat
More Synonyms of rat
rat in British English
(ræt)
noun
1.
any of numerous long-tailed murine rodents, esp of the genus Rattus, that are similar to but larger than mice and are now distributed all over the world
See also brown rat, black rat
2. informal
a person who deserts his or her friends or associates, esp in time of trouble
3. informal
a worker who works during a strike; blackleg; scab
4. slang, mainly US
an informer; stool pigeon
5. informal
a despicable person
6. smell a rat
verbWord forms: rats, ratting or ratted
7. (intransitive; usually foll byon) informal
a.
to divulge secret information (about); betray the trust (of)
b.
to default (on); abandon
he ratted on the project at the last minute
8. (intransitive)
to hunt and kill rats
Derived forms
ratlike (ˈratˌlike)
adjective
Word origin
Old English rætt; related to Old Saxon ratta, Old High German rato
rat in American English
(ræt)
noun
1.
any of numerous long-tailed rodents of various families (esp. Muridae and Cricetidae)resembling, but larger than, the mouse: rats are very destructive pests and carriers of highly contagious diseases, as bubonic plague and typhus
2. US
a small pad formerly used in certain styles of women's coiffures to make the hair look thicker
3. Slang
a sneaky, contemptible person
; specif.,
a.
an informer; stool pigeon
b.
a worker who is a scab
c.
a person who deserts or betrays a cause
4. Slang
a person who spends a great deal of time at, in, or on a (specified) place
a gym rat, a mall rat
verb intransitiveWord forms: ˈratted or ˈratting
5.
to hunt for rats, esp. with dogs
6. Slang
a.
to desert or betray a cause, movement, etc. as rats are reputed to desert a sinking ship
b.
to act as a stool pigeon; inform (on)
verb transitive US
7.
to tease (the hair)
Idioms:
smell a rat
Word origin
ME ratte < OE ræt, akin to Ger ratz, ratte < PGmc *ratto < ? IE base *red-, *rōd-, to scratch, gnaw > L radere, to scrape, rodere, to gnaw
And, like humans, rats enjoy tickling only when already in a good mood.
The Sun (2016)
They could have escaped like sewer rats.
The Sun (2013)
When she opened it she found four dead rats.
The Sun (2009)
Tests on rats showed it killed off a protein which protects the heart.
The Sun (2010)
They are as boring as lab rats.
Times, Sunday Times (2016)
We can expect to be overrun by rats now gigantic from eating rubbish.
The Sun (2010)
Are these giant rats on steroids or just vigorously exercising?
The Sun (2010)
Pest control was called in after dead rats and mice were found inside.
Times, Sunday Times (2014)
The lady could not have been kinder to her lab rats.
Times, Sunday Times (2013)
His insights into the lives of those young people now being called feral rats was gripping.
Times, Sunday Times (2011)
These super rats are now being seen all over the country.
The Sun (2015)
At the time he was working with female rats, using a new technique to listen to the neurons firing in their brains.
Times, Sunday Times (2013)
Word lists with
rat
rodent
In other languages
rat
British English: rat /ræt/ NOUN
A rat is an animal which has a long tail and looks like a large mouse.
...experiments with rats.
American English: rat
Arabic: جُرَذ
Brazilian Portuguese: rato-preto
Chinese: 老鼠
Croatian: štakor
Czech: krysa
Danish: rotte
Dutch: rat
European Spanish: rata
Finnish: rotta
French: rat
German: Ratte
Greek: αρουραίος
Italian: topo
Japanese: ドブネズミ
Korean: 쥐
Norwegian: rotte
Polish: szczur
European Portuguese: ratazana
Romanian: șobolan
Russian: крыса
Latin American Spanish: rata
Swedish: råtta
Thai: หนู
Turkish: sıçan
Ukrainian: щур
Vietnamese: con chuột con vật
British English: rat VERB
If someone rats on you, they tell someone in authority about things that you have done, especially bad things.
They were accused of encouraging children to rat on their parents.
American English: rat
Brazilian Portuguese: delatar
Chinese: 告发
European Spanish: chivarse
French: moucharder
German: verpfeifen
Italian: fare la spia
Japanese: 密告する
Korean: 밀고하다
European Portuguese: delatar
Latin American Spanish: deschavar
All related terms of 'rat'
de-rat
to remove rats from (a place)
gym rat
a person who spends a lot of time exercising at a gymnasium
rat run
A rat run is a small street which drivers use during busy times in order to avoid heavy traffic on the main roads.
rat-tat
the sound of knocking on a door
rug rat
a child not yet walking
black rat
a common rat , Rattus rattus : a household pest that has spread from its native Asia to all countries
brown rat
a common brownish rat , Rattus norvegicus : a serious pest in all parts of the world
cane rat
a tropical African cavy-like hystricomorph rodent , Thryonomys swinderianus, that lives in swampy regions: family Thryonomyidae
hood rat
a young promiscuous woman from an impoverished urban area
love rat
Journalists sometimes use love rat to refer to a man who treats his partner in a cruel way, especially by having sexual relationships with other people.
mall rat
Mall rats are young people who spend a lot of time hanging around in shopping malls with their friends .
Māori rat
a small brown rat , Rattus exulans , native to New Zealand
mole rat
any burrowing molelike African rodent of the family Bathyergidae
moon rat
a ratlike SE Asian nocturnal mammal, Echinosorex gymnurus, with greyish fur and an elongated snout : family Erinaceidae ( hedgehogs ): the largest living insectivore
pack rat
any rat of the genus Neotoma, of W North America, having a long tail that is furry in some species: family Cricetidae
rat-arsed
drunk
rat fink
a person who is obnoxious or contemptible
rat mite
a widespread tropical mite ( Ornithonyssus bacoti ) of the same order (Parasitiformes) as ticks : it is carried by rats and can cause skin inflammations or transmit typhus to human beings by its bite
rat pack
People sometimes refer to the group of journalists and photographers who follow famous people around as the rat pack , especially when they think that their behaviour is unacceptable .
rat race
If you talk about getting out of the rat race , you mean leaving a job or way of life in which people compete aggressively with each other to be successful .
rat snake
any of various nonvenomous rodent-eating colubrid snakes , such as Elaphe obsoleta of North America and Ptyas mucosus of Asia
rat tail
a hair style characterized by a long thin tail of hair growing at the back of the head
rat tamer
a psychologist or psychiatrist
rat trap
a device for catching rats
rink rat
a young person who carries out chores at an ice-hockey rink in return for free skating time
sewer rat
a common brownish rat , Rattus norvegicus : a serious pest in all parts of the world
water rat
any of several small amphibious rodents , esp the water vole or the muskrat
wharf rat
any rat , usually a brown rat, that infests wharves
white rat
a white variety of the brown rat ( Rattus norvegicus ), used extensively in scientific research
wood rat
→ pack rat
desert rat
a jerboa , Jaculus orientalis, inhabiting the deserts of N Africa
Norway rat
→ brown rat
pocket rat
→ kangaroo rat (sense 1 )
pouched rat
See pocket gopher
rat-a-tat
You use rat-a-tat to represent a series of sharp , repeated sounds , for example the sound of someone knocking at a door .
rat-catcher
a person whose job is to destroy or drive away vermin , esp rats
rat poison
a substance used to poison rats
rat-running
the practice of driving through residential side streets to avoid congested main roads
bandicoot rat
any of three burrowing rats of the genera Bandicota and Nesokia , of S and SE Asia : family Muridae
kangaroo rat
any small leaping rodent of the genus Dipodomys, related to the squirrels and inhabiting desert regions of North America, having a stocky body and very long hind legs and tails : family Heteromyidae
rat-catching
the job of destroying or driving away vermin , esp rats
rat-infested
(of a place or vessel ) that has many rats
rat kangaroo
any of several ratlike kangaroos of the genera Bettongia, Potorous, Aepyprymnus, etc, found on the Australian mainland and in Tasmania
rat-tat-tat
the sound of knocking on a door
smell a rat
to suspect that something is wrong in a particular situation, for example that someone is trying to deceive you or harm you
the rat race
a job or way of life in which people compete aggressively with each other in order to be successful
naked mole rat
a nearly hairless rodent , Heterocephalus glaber , of eastern African dry steppes and savannas , having two protruding upper and lower front teeth and living entirely underground in colonies , based on a single breeding female and specialized workers of both sexes
rat-a-tat-tat
the sound of knocking on a door
to smell a rat
If you smell a rat , you begin to suspect or realize that something is wrong in a particular situation , for example that someone is trying to deceive you or harm you.
look like a drowned rat
to be very wet , for example because you have been caught in the rain or because your hair is wet
Chinese translation of 'rat'
rat
(ræt)
n(c)
(Zool) 田鼠 (tiánshǔ) (只, zhī)
(inf, = person) 卑鄙小人 (bēibǐ xiǎorén)
1 (noun)
Definition
someone who is disloyal or treacherous
He was known as `The Rat', even before the bribes had come to light.
Synonyms
traitor
Some say he's a traitor to the working class.
grass (British, informal)
He preferred to take the rap rather than be a grass.
betrayer
a traitor and betrayer
deceiver
He was condemned as a liar, cheat and deceiver.
informer
two men suspected of being police informers
defector
deserter
He was a deserter from the army.
double-crosser
quisling
They called him a quisling.
stool pigeon
nark (British, Australian, New Zealand, slang)
snake in the grass
two-timer (informal)
fizgig (Australian, slang)
2 (noun)
Definition
someone who is disloyal or treacherous
What did you do with the gun you took from that little rat?
Synonyms
rogue
He wasn't a rogue at all.
scoundrel (old-fashioned)
He is a lying scoundrel.
heel (slang)
Suddenly I feel like a total heel.
shit (taboo, slang)
As I said, in many ways he was a shit.
bastard (informal, offensive)
I don't trust the bastard.
cad (old-fashioned, informal, British)
You're nothing but a scoundrel and a cad, sir!
bounder (old-fashioned, slang, British)
rotter (slang, mainly British)
The man's an absolute rotter!
bad lot
shyster (informal, mainly US)
ratfink (slang, mainly US, Canadian)
wrong 'un (slang)
Phrasal verbs
See rat on someone
See rat on something
idiom
See smell a rat
Additional synonyms
in the sense of betrayer
a traitor and betrayer
Synonyms
traitor,
deceiver,
informer,
renegade,
defector,
conspirator,
Judas,
deserter,
double-crosser (informal),
turncoat,
quisling,
apostate,
miscreant,
snake in the grass,
back-stabber,
fizgig (Australian, slang)
in the sense of cad
Definition
a man who behaves dishonourably
You're nothing but a scoundrel and a cad, sir!
Synonyms
scoundrel (slang),
rat (informal),
bounder (British, old-fashioned, slang),
cur,
knave (archaic),
rotter (slang, British),
heel,
scumbag (slang),
churl,
dastard (archaic),
wrong 'un (slang)
in the sense of deceiver
He was condemned as a liar, cheat and deceiver.
Synonyms
liar,
fraud (informal),
cheat,
fake,
betrayer,
crook (informal),
pretender,
deluder,
hypocrite,
charlatan,
trickster,
conman or woman (informal),
con artist (informal),
sharper,
impostor,
fraudster,
swindler,
dissembler,
inveigler,
mountebank,
snake in the grass,
grifter (slang, US, Canadian),
double-dealer,
chiseller (informal),
cozener,
rorter (Australian, slang),
rogue trader
Synonyms of 'rat'
rat
Explore 'rat' in the dictionary
Additional synonyms
in the sense of deserter
He was a deserter from the army.
Synonyms
defector,
runaway,
fugitive,
traitor,
renegade,
truant,
escapee,
absconder,
apostate
in the sense of grass
Definition
a person who informs, usually on criminals
He preferred to take the rap rather than be a grass.