The Collaborative International Dictionary of English v.0.48:
billystick \billystick\ n. a policeman's club. Syn: truncheon, nightstick, billy, billy club. [WordNet 1.5]WordNet (r) 3.0 (2006):
billystick n 1: a short stout club used primarily by policemen [syn: truncheon, nightstick, baton, billy, billystick, billy club]