[rat] n [ME, fr. OE raet; akin to OHG ratta rat and perh. to L rodere to gnaw--more at rodent] (bef. 12c) 1 a: any of numerous rodents (Rattus and related genera) differing from the related mice by considerably larger size and by structural details (as of the teeth) b: any of various similar rodents
2: a contemptible person: as a: one who betrays or deserts friends or associates b: scab 3b c: informer 2
3: a pad over which a woman's hair is arranged
4: a person who spends much time esp. idly in a specified place "a mall ~" -- rat.like adj
[2]rat vb rat.ted ; rat.ting vi (1812) 1: to betray, desert, or inform on one's associates--usu. used with on
2: to catch or hunt rats
3: to work as a scab ~ vt: to give (hair) the effect of greater quantity by use of a rat