v. 1 confirm or settle (an argument, bargain, etc.) conclusively. 2 (of boxers etc.) become too closely engaged. 3 secure (a nail or rivet) by driving the point sideways when through. n. 1 a clinching action. b clinched state. 2 colloq. embrace. [var. of CLENCH] clincher n. colloq. point or remark that settles an argument etc.
