three cardinal sins [三逆・三逆罪] ( san-gyaku or san-gyakuzai): Three grave offenses committed by Devadatta. Constituting three of the five cardinal sins, or the five most serious offenses in Buddhism, they are (1) killing an arhat, (2) injuring the Buddha, and (3) causing disunity in the Buddhist Order. The other two of the five cardinal sins are killing one’s father and killing one’s mother. See also Devadatta.