noun
- 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
- ☆ a small pad formerly used in certain styles of women's coiffures to make the hair look thicker
- Slang a sneaky, contemptible person; specif.,
- an informer; stool pigeon
- a worker who is a scab
- a person who deserts or betrays a cause
- Slang a person who spends a great deal of time at, in, or on a (specified) place: a gym rat, a mall rat
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
intransitive verb ratted, ratting
- to hunt for rats, esp. with dogs
- 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)