I. ˈtän(t)-shər noun
Etymology: Middle English, from Anglo-French, from Medieval Latin tonsura, from Latin, act of shearing, from tonsus, past participle of tondēre to shear — more at tome
Date: 14th century
1. : the Roman Catholic or Eastern rite of admission to the clerical state by the clipping or shaving of a portion of the head
2. : the shaven crown or patch worn by monks and other clerics
3. : a bald spot resembling a tonsure
II. transitive verb
( ton·sured ; ton·sur·ing ˈtän(t)-sh(ə-)riŋ)
Date: 1706
: to shave the head of ; especially : to confer the tonsure upon