Source : Webster's Revised Unabridged Dictionary (1913)

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.

Source : WordNet®

venesection
     n : surgical incision into a vein; used to treat hemochromatosis
         [syn: {phlebotomy}]