COCCYX

[coc.cyx] n, pl coc.cy.ges also coc.cyx.es [NL, fr. Gk kokkyx cuckoo, coccyx; fr. its resemblance to a cuckoo's beak] (1615): a small bone that articulates with the sacrum and that usu. consists of four fused vertebrae which form the terminus of the spinal column in humans and tailless apes