Source : Webster's Revised Unabridged Dictionary (1913)

Ibex \I"bex\, n.; pl. E. {Ibexes}, L. {Ibices}. [L., a kind of
   goat, the chamois.] (Zo["o]l.)
   One of several species of wild goats having very large,
   recurved horns, transversely ridged in front; -- called also
   {steinbok}.

   Note: The Alpine ibex ({Capra ibex}) is the best known. The
         Spanish, or Pyrenean, ibex ({C. Hispanica}) has
         smoother and more spreading horns.