Source : Webster's Revised Unabridged Dictionary (1913)

Jeer \Jeer\, v. i. [imp. & p. p. {Jeered}; p. pr. & vb. n.
   {Jeering}.] [Perh. a corrup. of cheer to salute with cheers,
   taken in an ironical sense; or more prob. fr. D. gekscheren
   to jeer, lit., to shear the fool; gek a fool (see 1st {Geck})
   + scheren to shear. See {Shear}, v.]
   To utter sarcastic or scoffing reflections; to speak with
   mockery or derision; to use taunting language; to scoff; as,
   to jeer at a speaker.

         But when he saw her toy and gibe and jeer. --Spenser.

   Syn: To sneer; scoff; flout; gibe; mock.