Drill1  —n. 1 tool or machine for boring holes, sinking wells, etc. 2 instruction in military exercises. 3 routine procedure in an emergency (fire-drill). 4 thorough training, esp. By repetition. 5 colloq. Recognized procedure (what's the drill?). —v. 1 a make a hole in or through with a drill. B make (a hole) with a drill. 2 train or be trained by drill. [dutch]