biceps brachii /bī″seps brā″kē·ī/ [L, bis, twice, caput, head, bracchii, arm] , the long fusiform muscle of the upper arm on the anterior surface of the humerus, arising in two heads from the scapula. It flexes the arm and the forearm and supinates the hand. Also called biceps, biceps flexor cubiti. Compare brachialis, triceps brachii.
