Twibil \Twi"bil\, n. [AS. twibill; twi- (in comp.) two + bill, bil, an ax hoe, bill. See {Twice}, and {Bill} a cutting instrument.] 1. A kind of mattock, or ax; esp., a tool like a pickax, but having, instead of the points, flat terminations, one of which is parallel to the handle, the other perpendicular to it. [Prov. Eng.] 2. A tool for making mortises. [Obs.] 3. A reaping hook.