| Noun | 1. | pelvic arch - the structure of the vertebrate skeleton supporting the lower limbs in humans and the hind limbs or corresponding parts in other vertebratescoccyx, tail bone - the end of the vertebral column in humans and tailless apes hipbone, innominate bone - large flaring bone forming one half of the pelvis; made up of the ilium and ischium and pubis ilium - the upper and widest of the three bones making up the hipbone os pubis, pubic bone, pubis - one of the three sections of the hipbone; together the two pubic bones form the front of the pelvis sacrum - wedge-shaped bone consisting of five fused vertebrae forming the posterior part of the pelvis; its base connects with the lowest lumbar vertebra and its tip with the coccyx girdle - an encircling or ringlike structure appendicular skeleton - the part of the skeleton that includes the pectoral girdle and the pelvic girdle and the upper and lower limbs | |