'Billy' definitions:

Definition of 'billy'

(from WordNet)
noun
A short stout club used primarily by policemen [syn: truncheon, nightstick, baton, billy, billystick, billy club]
noun
Male goat [syn: billy, billy goat, he-goat]

Definition of 'Billy'

From: GCIDE
  • Billy \Bil"ly\, n.
  • 1. A club; esp., a policeman's club. Also called billy club [1913 Webster +PJC]
  • 2. (Wool Manuf.) A slubbing or roving machine. [1913 Webster]