the world > life > the body > structural parts > bone or bones > bony support for limbs > pelvis > [noun] > coccyx
coccyx1615
rump-bone1615
cuckoo-bone1668
1668 N. Culpeper & A. Cole tr. T. Bartholin Anat. (new ed.) iv. xv. 351 Os Coccygis the Cockow-bone, so called from the shape it hath of a Cuckows-bill.