[ 'kɒksɪks ]
■ noun ( plural coccyges -ɪdʒi:z or ~es ) a small triangular bone at the base of the spinal column in humans and some apes, formed of fused vestigial vertebrae.
Derivatives
coccygeal kɒk'sɪdʒɪəl adjective
Origin
C16: via L. from Gk kokkux 'cuckoo' (because the shape of the human bone resembles the cuckoo's bill).