calcaneus (n.)

"heel-bone," 1751, from Latin (os) calcaneum "bone of the heel," from calcem (nominative calx (1)) "heel," a word of uncertain origin, perhaps from Etruscan. De Vaan lists as possible cognates Old Prussian culczi "hip," Lithuanian kulkšnis "ankle-(bone)," Bulgarian kalka "hip, thigh." Related: Calcaneal.