rat

plural rats

1. Any of the numerous members of several rodent families that usually have short limbs, a pointy snout, a long, hairless tail, and a body length greater than about 12 cm, or 5 inches.
2. biologyA medium-sized rodent belonging to the genus Rattus.

   Similar studies of rats have employed four different intracranial resorbable, slow sustained release systems—surgical foam, a thermal gel depot, a microcapsule or biodegradable polymer beads.

   2013 May-June, Charles T. Ambrose, “Alzheimer’s Disease”, in American Scientist, volume 101, number 3, page 200

3. informalA person who is known for betrayal.

   rat bastard

   4 more examples

   Near-synonyms: rogue, scoundrel, snake; see also Thesaurus:villain

   He’s more a man than any pair of rats of you in this here house.

   1881–1882, Robert Louis Stevenson, Treasure Island, London; Paris: Cassell & Company, published 14 November 1883, →OCLC

   What a rat, leaving us stranded here!

   "Ah, so you damn rat, this is a put-up job eh?"

   1936, F.J. Thwaites, chapter XVIII, in The Redemption, Sydney: H. John Edwards, published 1940, page 185

   Synonyms: fink, ratfink, betrayer, snake in the grass, quisling, traitor, backstabber, betrayer

4. informalAn informant or snitch.

   Synonyms: fink, ratfink, stool pigeon, abaddon, accuser, beefer, bewrayer, bigmouth

5. informalA scab: a worker who acts against trade union policies.

   Synonyms: fink, ratfink, blackleg, knobstick, scalie

6. slangA person who routinely spends time at a particular location.

   Our teenager has become a mall rat.

   1 more example

   He loved hockey and was a devoted rink rat.

7. A wad of shed hair used as part of a hairstyle.
8. A roll of material used to puff out the hair, which is turned over it.
9. UKslangvulgarnorth-west LondonVagina, vulva.

   Get your rat out.

   1 more example

   I don't need no dating app to tell me if I look like crap / To tell me if I'm thin or fat, to tell me should I shave my rat / I don't need no radio, no MTV, no BBC / I just need a bubble bath to set me on a higher path

   2022, Chambers Hester Louise, Champion Michael James, Teasdale Rhian Louise, “Too Late Now”, in Wet Leg, performed by Wet Leg, Domino, →OCLC

   Synonyms: beaver, pussy, axe wound, badly packed kebab, bearded clam, beaver, beef curtains, burger

10. abbreviationellipsisinformalEllipsis of muskrat.

    The price of rats began to rise and soon after the marsh froze over, spearing rats began, which was done with a one tine three-eighths inch steel rod, with a wooden handle […]

    1910, L. W. Pierce, “Muskrats are fast disappearing”, in Hunter-trader-trapper, page 70

    1 more example

    Where natural marshes, or natural foods are found, are best places for raising muskrats. Louisiana and other southern states raise millions of rats, but they do not bring as good prices as northern raised ones. Delaware and Maryland have famed marshes. Other states are becoming noted for muskrat raising, also.

    1929, E. J. Dailey, in Hardings Magazine's Question Box, printed in Fur Fish Game, page 73

present singular third person rats · participle present ratting · participle past ratted · past ratted

1. usuallyTo hunt or kill rats.First known use 19th c.
2. intransitiveTo betray a political party, cause or principle; to betray someone, to desert a person or thing.First known use 19th c.
3. informalintransitiveTo work as a scab, going against trade union policies.First known use 19th c.
4. USTo backcomb (hair).First known use 20th c.

   In 1962, the higher a girl's hair was ratted the more available she was, it was simply understood.

   2021, Rickie Lee Jones, Last Chance Texaco, Grove Press, published 2022, page 31

5. intransitivewith on or outTo inform on someone; to betray someone to the police or authorities.First known use 20th c.

   He ratted on his coworker.

   1 more example

   He is going to rat us out!

plural rats

1. regionalA scratch or a score.
2. regionalnauticalA place in the sea with rapid currents and crags where a ship is likely to be torn apart in stormy weather.

present singular third person rats · participle present ratting · participle past ratted · past ratted

1. regionalTo scratch or score.

   He ratted a vertical line on his face with a pocket knife.

2. obsoleterareregionalTo tear, rip, rend.

   Ratted to shreds.

3. Damn, drat, blast; used in oaths.

   “But, rat me, sir,” cried Foster in bewilderment, “tis too generous—'pon honour it is. I can't consent to it. No, rat me, I can't.”

   1904, Rafael Sabatini, chapter XXVI, in The Tavern Knight

plural rats

1. slanggovernmentA ration.

   1 more example

   With regards to the testing of his product, the initial blood analysis had come back confirming huge, distinctive nutritional superiority for Stewart's military ration pack. Given that the policy of the British Army is to be fully ready for war at the drop of a hat, he was sitting on the potential of supplying new rats for the entire army […]

   2014, John, Buffoon, page 243

present singular third person rats · participle present ratting · participle past ratted · past ratted

1. transitivecomputingTo hack someone with a remote-access Trojan.

1. The first of the 12-year cycle of animals which appear in the Chinese zodiac related to the Chinese calendar.

plural RATs

1. abbreviationcountableinitialismmedicineInitialism of rapid antigen test.
2. abbreviationcountableinitialismpublic transportationInitialism of Rapid Area Transit.
3. abbreviationcountableinitialismaeronauticsInitialism of ram air turbine.
4. abbreviationcountableinitialismcomputingInitialism of remote-access Trojan.
5. abbreviationinitialismuncountablehuman sciencesInitialism of relevant alternatives theory.

present singular third person RATs · participle present RATing · participle past RATed · past RATed · participle past RAT'd · past RAT'd

1. transitivecomputingTo hack someone with a remote-access Trojan.