Dog  —n. 1 four-legged flesh-eating animal akin to the fox and wolf, and of many breeds. 2 male of this, or of the fox or wolf. 3 colloq. A despicable person. B person of a specified kind (lucky dog). 4 mechanical device for gripping. 5 (in pl.; prec. By the) colloq. Greyhound-racing. —v. (-gg-) follow closely; pursue, track.  go to the dogs slang deteriorate, be ruined. Like a dog's dinner colloq. Smartly or flashily (dressed etc.). Not a dog's chance no chance at all. [old english]