left brachiocephalic vein [ME, left, weak; Gk, brachys, short, kephale, head] , a vessel about 6 cm long that starts in the root of the neck at the junction of the internal jugular and the subclavian veins on the left side and runs obliquely across the thorax to join the right brachiocephalic vein and form the superior vena cava. Also called left innominate vein. Compare right brachiocephalic vein.
