brunt; sharp edge of an argument; cutting remark
Rare literary term, originally from Zen Buddhism referring to the sharp point of a master's words that cuts through delusion. In modern contexts, it can mean the brunt or sharp edge of a verbal attack or argument.
Faced with his sharp, cutting words, the opponent could say nothing.
In Zen dialogue, the master's sharp retort cuts through the disciple's delusion.
Compound of 機 (opportunity, mechanism, or subtle function) and 鋒 (point of a sword). The exact historical derivation is uncertain; the term is strongly associated with Zen usage where it denotes the sharp, spontaneous response of an enlightened master.