n. A rodent of some of the larger species of the genus Mus, as M. rattus, the black rat, and M. decumanus, the gray, brown, or Norway rat: distinguished from mouse.n. Any rodent of the family Muridæ; a murine; in the plural, the Muridæ.n. Any rodent of the suborder Myomorpha.n. Some other rodent, or some insectivore, marsupial, or other animal like or likened to a rat.n. A person who is considered to act in some respect in a manner characteristic of rats: so called in opprobrium.n. A workman who accepts lower wages than those current at the time and place or required by an authorized scale, or one who takes a position vacated by a striker, or one who refuses to strike when others do.n. A clergyman: so called in contempt.n. Something suggesting the idea of a rat, as a curving roll of stuffed cloth or of crimped hair-work, with tapering ends, formerly (about 1860–70) and still occasionally used by women to puff out the hair, which was turned over it.n. Same as bandicoot, 2.To catch or kill rats; follow the business of a ratter or rat-catcher.To go over from one party or cause to another, especially from a party or cause that is losing or likely to lose, as rats run from a falling house; desert one's party or associates for advantage or gain; become a renegade.To work for less than current wages, to refuse to strike with fellow-workmen, or to take the place of one who has struck: often with indefinite it. See rat, n., 5 .To puff out (the hair) by means of a rat. See rat, n., 6.To displace or supplant union workers in: as. to rat an office or a shop.n. A rag; tatter.To tear.A term of objurgation, used in the imperative.A Middle English contracted form of redeth, the third person singular present indicative of read.n. plural An exclamation used to indicate incredulity or ironical disagreement with a statement; humbug.
