[ton.sure] n [ME, fr. ML tonsura, fr. L, act of shearing, fr. tonsus, pp. of tondere to shear--more at tome] (14c) 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
[2]tonsure vt ton.sured ; ton.sur.ing (1706): to shave the head of; esp: to confer the tonsure upon