—n. 1. any small carnivore of the genus Mustela, of the family Mustelidae, having a long, slender body and feeding chiefly on small rodents.
2. any of various similar animals of the family Mustelidae.
3. a cunning, sneaky person.
4. a tracked vehicle resembling a tractor, used in snow.
5. Slang.an informer; stool pigeon.
—v.i. 1. to evade an obligation, duty, or the like; renege (often fol. by out): That's one invitation I'd like to weasel out of. 2. to use weasel words; be ambiguous; mislead: Upon cross-examination the witness began to weasel. 3. Slang.to inform.