Source : Webster's Revised Unabridged Dictionary (1913)

Halberd \Hal"berd\ (h[o^]l"b[~e]rd; 277), n. [F. hallebarde; of
   German origin; cf. MHG. helmbarte, G. hellebarte; prob.
   orig., an ax to split a helmet, fr. G. barte a broad ax
   (orig. from the same source as E. beard; cf. Icel. bar[eth]a,
   a kind of ax, skegg beard, skeggja a kind of halberd) + helm
   helmet; but cf. also MHG. helm, halm, handle, and E. helve.
   See {Beard}, {Helmet}.] (Mil.)
   An ancient long-handled weapon, of which the head had a point
   and several long, sharp edges, curved or straight, and
   sometimes additional points. The heads were sometimes of very
   elaborate form. [Written also {halbert}.]

Source : WordNet®

halberd
     n : a pike fitted with an ax head