ˈklinchə(r) noun
( -s )
: one that clinches: as
a. : a decisive fact, argument, act, or remark
the expense was the clincher that persuaded us to give up the enterprise
b. : a machine in commercial canning for positioning a lid loosely on the can prior to sealing it
c. or clincher tire : an automobile tire with flanged beads fitting into the wheel rim