Source : Webster's Revised Unabridged Dictionary (1913)

Poniard \Pon"iard\, n. [F. poignard (cf. It. pugnale, Sp.
   pu[~n]al), fr. L. pugio, -onis; probably akin to pugnus fist,
   or fr. pugnus fist, as held in the fist. See {Pugnacious}.]
   A kind of dagger, -- usually a slender one with a triangular
   or square blade.

         She speaks poniards, and every word stabs. --Shak.

Poniard \Pon"iard\, v. t. [imp. & p. p. {Poniarded}; p. pr. &
   vb. n. {Poniarding}.]
   To pierce with a poniard; to stab. --Cowper.

Source : WordNet®

poniard
     n : a dagger with a slender blade [syn: {bodkin}]
     v : stab with a poniard