noun
apostate priest; fallen monk
A derogatory term for a Buddhist priest who has abandoned their vows or leads a corrupt life. Often used in historical or literary contexts.
その堕落坊主は寺を捨てて、酒と女に溺れた。
The apostate priest abandoned the temple and indulged in drink and women.
破戒僧 is a more formal term for a priest who breaks precepts, while 堕落坊主 is more colloquial and contemptuous.
Compound of 堕落 (daraku, 'corruption, depravity') and 坊主 (bōzu, 'Buddhist priest'). The exact historical origin is uncertain, but it likely emerged as a derogatory label for priests who strayed from monastic discipline.