ETYM Latin, two-headed; bis twice + caput head. Related to Capital.
Any skeletal muscle having two origins (but especially the muscle that flexes the forearm).
A muscle having two heads: as the large flexor muscle of the front of the upper arm; the large flexor muscle of the back of the upper leg.
Koji ima dve glave, dva lica (nadimak rimskog boga Janusa); dvoglavi ručni mišić.