coccyx

 
Pronunciation: /ˈkɒksɪks/

noun (plural coccyges /-ɪdʒiːz/ or coccyxes)

  • a small triangular bone at the base of the spinal column in humans and some apes, formed of fused vestigial vertebrae.

Derivatives

coccygeal

Pronunciation: /kɒkˈsɪdʒɪəl/
adjective

Origin:

late 16th century: via Latin from Greek kokkux 'cuckoo' (because the shape of the human bone resembles the cuckoo's bill)