expression, ichidan verb
be tonsured; have one's head shaved
Literally means to shave one's head, often in a religious context. Can be used figuratively for becoming a monk.
彼は出家して頭を丸めた。
He entered the priesthood and shaved his head.
expression, ichidan verb
become a monk
Figurative extension of the head-shaving sense, referring to the act of becoming a Buddhist monk.
After much anguish, he decided to become a monk.