Source : Webster's Revised Unabridged Dictionary (1913)

Calcaneum \Cal*ca"ne*um\n.; pl. E. {-neums}, L. {-nea}. [L. the
   heel, fr. calx, calcis, the heel.] (Anal.)
   One of the bones of the tarsus which in man, forms the great
   bone of the heel; -- called also {fibulare}.