From Latintonsūra ("a clipping, trimming"), from tondeŠ("shear, clip, trim").
Full definition of tonsure
Verb
(Christianity) To subject to the often ritualshaving of the crown of the head as a sign of humility and one's religious vocation. Some tonsures were more dramatic than others, leaving only a fringe of hair. Abolished by Vatican II in the Roman Catholic Church.