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.
Slang. a scoundrel.
Slang.
a person who abandons or betrays his or her party or associates, especially in a time of trouble.
an informer.
a scab laborer.
Slang. a person who frequents a specified place: a mall rat;gym rats.
a pad with tapered ends formerly used in women's hairstyles to give the appearance of greater thickness.
interjection
rats,Slang. (an exclamation of disappointment, disgust, or disbelief.)
verb (used without object),rat·ted,rat·ting.
Slang.
to desert one's party or associates, especially in a time of trouble.
to turn informer; squeal: He ratted on the gang, and the police arrested them.
to work as a scab.
to hunt or catch rats.
verb (used with object),rat·ted,rat·ting.
to dress (the hair) with or as if with a rat.
Verb Phrases
rat out,Slang. to inform on: He ratted out his partners in exchange for a lighter sentence.
Idioms for rat
smell a rat, to suspect or surmise treachery; have suspicion: After noting several discrepancies in his client's story, the attorney began to smell a rat.
Origin of rat
First recorded before 1000; Middle English rat(t)te, Old English ræt; cognate with Dutch rat, German Ratz, Ratte
I have no idea if he is the “friend” who ratted me out to Joseph Nye.
Damn Right I Taped Kerry’s ‘Apartheid’ Talk|Josh Rogin|May 2, 2014|DAILY BEAST
“I ratted on the Aryan Brotherhood,” said former member Sullivan.
What’s So Scary About the Texas Aryan Brotherhood? Take a Look at the Indictments|Christine Pelisek|April 3, 2013|DAILY BEAST
But every so often he mutters that he’ll get even with someone by the name of Otto—a fellow sailor who ‘ratted.
The Secret Pact|Mildred A. Wirt
Only about that dreadful Mr Trenchard; you know the reason why he ratted?
Sybil|Benjamin Disraeli
If claims are ratted it is said there are strangers about, and the miners deal with rats according to their own ideas of justice.
The Black Opal|Katharine Susannah Prichard
Matthew, we know, played the traitor; and though Mackworth ratted to my own side, I fear it must be confessed that he did rat.
Essays in English Literature, 1780-1860|George Saintsbury
You remember how Anchor Joe talked about someone who had ‘ratted’?
The Secret Pact|Mildred A. Wirt
British Dictionary definitions for rat
rat
/ (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 worldSee also brown rat, black rat
informala person who deserts his or her friends or associates, esp in time of trouble
informala worker who works during a strike; blackleg; scab
slang, mainlyUSan informer; stool pigeon
informala despicable person
smell a ratto detect something suspicious
verbrats, rattingorratted
(intr usually foll by on) informal
to divulge secret information (about); betray the trust (of)
to default (on); abandonhe ratted on the project at the last minute
to hunt and kill rats
See also rats
Derived forms of rat
ratlike, adjective
Word Origin for rat
Old English rætt; related to Old Saxon ratta, Old High German rato
Any of various long-tailed rodents of the genus Rattus and related genera, including certain strains used in scientific research and certain species that are vectors for various diseases.