rat

rat

1. slang A despicable, contemptible, and untrustworthy person. Her ex-husband turned out to be a real rat. I'm so glad she divorced him when she did.
2. slang Someone who provides confidential and damaging information to another person or group; an informant. The boss thinks we've got a rat in our ranks telling the police about our movements.
3. slang Someone who spends an inordinate amount of time at some particular recreational location. Used in combinations. I turned into a real gym rat during college. I go pretty much every day now. She has always been a rink rat, ever since she was a kid, so it's no surprise to me that she ended up playing ice hockey professionally.
4. slang Someone who continues working or is brought in to work during a strike; a scab. The company hired a bunch of rats from out of state to work the mines while we were on strike. After he crossed the picket line in '78, Tom was labeled a rat among his coworkers for the rest of his career.

rats

An exclamation of frustration, disappointment, or vexation. Oh, rats—I dropped another screw. A: "Sorry, I won't be able to come this Saturday." B: "Rats! OK, we'll try to get together some other time."
See also: rat
Farlex Dictionary of Idioms.

rat

verb
See rat on someone

rat

1. n. a wretched-acting person. (Also a term of address.) You dirty rat, you!
2.  Go to rat (on someone).
McGraw-Hill's Dictionary of American Slang and Colloquial Expressions
See:
  • drowned rat, like a/wet as a
  • frat-rat
  • hood rat
  • lab rat
  • like a drowned rat
  • like a rat up a drainpipe
  • like rats abandoning a sinking ship
  • like rats deserting a sinking ship
  • like rats from a sinking ship
  • like rats leaving a sinking ship
  • look like a drowned rat
  • pack rat
  • rat
  • rat (one) out
  • rat around
  • rat fink
  • rat on
  • rat on (one)
  • rat on someone
  • rat out
  • rat race
  • rat race, a
  • rat run
  • rat through (something)
  • rat-arsed
  • rathole
  • rats
  • Rats abandon a sinking ship
  • rats desert a sinking ship
  • rats deserting a sinking ship
  • rats leave a sinking ship
  • Rats!
  • ratted
  • rug rat
  • rugrat
  • sack rat
  • sewer rat
  • smell a rat
  • smell a rat, to
  • the rat race
  • the rats
  • winter rat
References in classic literature
Anna Maria!" squeaked the rat. There was a pattering noise and an old woman rat poked her head round a rafter.
But Tom Kitten has always been afraid of a rat; he never durst face anything that is bigger than--
"I've lost my dear son Thomas; I'm afraid the rats have got him." She wiped her eyes with an apron.
Original Peter Rabbit Books
"Trained rats!" Manuel Fonseca, the contortionist, exploded in the bar-room of the Hotel Annandale, after refusing to drink with Duckworth.
Out of thirty rats there were seven dead,--starved to death.
And his dear looked at him in all his imperturbable, complacent self-consciousness of kindness, and saw herself the little rural school-teacher who, with Ella Wheeler Wilcox and Lord Byron as her idols, and with the dream of herself writing "Poems of Passion," had come up to Topeka Town to be beaten by the game into marrying the solid, substantial business man beside her, who enjoyed delight in the spectacle of cats and rats walking the tight-rope in amity, and who was blissfully unaware that she was the Robin Redbreast in a cage that put all heaven in a rage.
Michael Brother of Jerry
Now as they were getting off, the Doctor noticed that a whole lot of rats were coming up from downstairs and leaving the ship as well.
"Ahem--er--you know of course that all ships have rats in them, Doctor, do you not?"
"And you have heard that rats always leave a sinking ship?"
Story of Doctor Dolittle
I love to read tales about rats. They make my flesh creep so.
Then there is the story of the Pied Piper of Hamelin, how first he piped the rats away, and afterward, when the mayor broke faith with him, drew all the children along with him and went into the mountain.
Idle Thoughts of an Idle Fellow
Nothing could be extracted from them on cross-examination except that there might have been rats in the house, though they were not aware of it.
On the second occasion she said it was required by the cook for ridding the lower part of the house of rats.
As for the rats, I left the killing of them to the cook and the other servants, just as I should have left any other part of the domestic business to the cook and the other servants.
Law and the Lady
Before, so as not to scare the rats in front of him, he had turned his dark lantern on himself, lighting up his own head; now, to hasten their flight, he lit the dark space in front of him.
Phantom of the Opera