lateral pectoral nerve, one of a pair of branches from the brachial plexus that, with the medial pectoral nerve, supplies the pectoral muscles. It lies lateral to the axillary artery, arises from the lateral cord of the plexus or from the anterior divisions of the superior and middle trunks just before they unite into the cord, and ends on the deep surface of the clavicular and the cranial sternocostal parts of the pectoralis major. Compare medial pectoral nerve.
