noun
also pelvic arch
: a bony or cartilaginous arch that supports the hind limbs of a vertebrate, that corresponds to the pectoral girdle of the forelimbs but is usually more rigid and firmly attached to the vertebral column, and that consists primitively of a single cartilage which is replaced in higher forms by paired innominate bones articulating solidly with the sacrum dorsally and with one another at the pubic symphysis