Inflected forms: pl. coc·cy·ges (kk-sjz, kks-jz) A small triangular bone at the base of the spinal column in humans and tailless apes, consisting of several fused rudimentary vertebrae. Also called tailbone.
ETYMOLOGY:
New Latin, from Greek kokkx, cuckoo, coccyx (from its resemblance to a cuckoo's beak).