Noun
The act or operation of opening a vein for letting blood; bloodletting; phlebotomy.
Source: Webster's dictionaryHe sought to locate the precise site for venesection in pleurisy within the framework of the classical method. Source: Internet
Galen, however, staunchly defended venesection in his three books on the subject Brain P (trans.) Galen on Bloodletting: A study of the origins, development, and validity of his opinions, with a translation of the three works. Source: Internet