The Collaborative International Dictionary of English v.0.48:
Venesection \Ve`ne*sec"tion\, n. [NL. venaesectio; L. vena vein + sectio section.] (Med.) The act or operation of opening a vein for letting blood; bloodletting; phlebotomy. [1913 Webster]WordNet (r) 3.0 (2006):
venesection n 1: surgical incision into a vein; used to treat hemochromatosis [syn: venesection, phlebotomy]