noun
also pectoral arch
: the bony or cartilaginous arch supporting the forelimbs of a vertebrate that corresponds to the pelvic girdle of the hind limbs but is usually not attached to the spinal column and that consists primitively of a single cartilage on each side which in higher forms becomes ossified, divided into the scapula above and the precoracoid and coracoid below, and complicated by the addition or substitution of one or more membrane bones and which in man is highly modified with the scapula alone of the original elements well developed, the coracoid being represented only by a process, and the precoracoid being replaced by the clavicle that connects the scapula with the sternum and is the only bony connection of the arm bones with the rest of the skeleton