‖ pterna|ˈptɜːrnə| [mod.L., a. Gr. πτέρνα heel.] †a.Anat. The heel-bone, os calcis. Obs. b.Ornith. The heel-pad or sole of the foot in birds. 1684tr.Blancard's Phys.Dict., Pterna, see Calx.1706Phillips, Pterna, the second Bone of the Foot.1895in Syd. Soc.Lex.