definition of
rat

[1] #1 rat n. any of various long-tailed rodents similar to but larger than a mouse. wn

[2] #2 rat v. desert one's party or group of friends, for example, for one's personal advantage. wn

[3] #3 rat n. [scab, strikebreaker, blackleg] someone who works (or provides workers) during a strike. wn

[4] #4 rat v. employ scabs or strike breakers in. wn

[5] #5 rat n. [rotter, dirty dog, skunk, stinker, stinkpot, bum, puke, crumb, lowlife, scum bag, so-and-so, git] a person who is deemed to be despicable or contemptible; "only a rotter would do that"; "kill the rat"; "throw the bum out"; "you cowardly little pukes!"; "the British call a contemptible person a 'git'". wn