Definition of 'rat'

COBUILD frequency band

rat

(ræt

)

Word forms: plural, 3rd person singular present tense 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.

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. intransitive 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.

4. intransitive verb

If someone rats on an agreement, they do not do what they said they would do.

[informal]

She claims he ratted on their divorce settlement.

See to smell a rat

More Synonyms of rat

Image of
rat

American English pronunciation

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British English pronunciation

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rat in American English

(ræt )

nounOrigin: 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

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.,

an informer; stool pigeon

a worker who is a scab

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: ratted, ratting

to hunt for rats, esp. with dogs

6. slang

to desert or betray a cause, movement, etc. as rats are reputed to desert a sinking ship

to act as a stool pigeon; inform (on)

verb transitive

7. US

to tease (the hair)

8. slang

to inform on or betray (someone) [with out]

his comrades will not rat him out

Idioms:

smell a rat

COBUILD frequency band

rat in American English

(ræt) (verb ratted, ratting)

noun

any of several long-tailed rodents of the family Muridae, of the genus Rattus and related genera, distinguished from the mouse by being larger

any of various similar or related animals

3. slang

a scoundrel

4. slang

a person who abandons or betrays his or her party or associates, esp. in a time of trouble

an informer

a scab laborer

5. slang

a person who frequents a specified place

mall rat

gym rat

a pad with tapered ends formerly used in women's hair styles to give the appearance of greater thickness

7. See smell a rat

interjection

8. See rats

intransitive verb

9. slang

to desert one's party or associates, esp. in a time of trouble

to turn informer; squeal

He ratted on the gang, and the police arrested them

to work as a scab

10.

to hunt or catch rats

transitive verb

11.

to dress (the hair) with or as if with a rat

Derived forms

ratlike

adjective

Word origin

[bef. 1000; ME rat(t)e, OE ræt; c. D rat, G Ratz, Ratte]

COBUILD frequency band

rat in British English

(ræt

)

noun

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

Examples of 'rat' in a sentence
rat

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The prison was swimming in drugs and swarming with rats.Are there rats in the stadium?Is there any other reaction to the subject of rats? Autumn cooling into winter also means rats are getting cold – and heading indoors.There are hundreds and hundreds of rats running around.And, like humans, rats enjoy tickling only when already in a good mood. Tests on rats showed it killed off a protein which protects the heart.They are as boring as lab rats.Pest control was called in after dead rats and mice were found inside.His insights into the lives of those young people now being called feral rats was gripping.

Word lists with
rat

rodent

Quick word challenge

Quiz Review

Question: 1

Score: 0 / 5

Which rodent am I?

any of several South American rodents of the genus Myoprocta, closely related to the agoutis but much smaller, with a white-tipped tail: family Dasyproctidae

acouchi agouti cavy

Which rodent am I?

a very small reddish-brown Eurasian mouse, Micromys minutus, inhabiting cornfields, hedgerows, etc, and feeding on grain and seeds: family Muridae

fieldmouse harvest mouse kangaroo rat

Which rodent am I?

any small Old World rodent of the family Gliridae, esp the Eurasian Muscardinus avellanarius, resembling a mouse with a furry tail

cavy dormouse hedgehog

Which rodent am I?

a gregarious burrowing hystricomorph rodent, Lagostomus maximus, of southern South America, similar to but larger than the chinchillas: family Chinchillidae

chinchilla paca viscacha

Which rodent am I?

an aquatic South American hystricomorph rodent, Myocastor coypus, introduced into Europe: family Capromyidae. It resembles a small beaver with a ratlike tail and is bred in captivity for its soft grey underfur

cavy chinchilla coypu

Your score: