[cinch] n [Sp cincha, fr. L cingula girdle, girth, fr. cingere] (1859) 1: a girth for a pack or saddle
2: a tight grip 3 a: a thing done with ease b: a certainty to happen
[2]cinch vt (1866) 1: to put a cinch on
2: to make certain: assure ~ vi: to tighten the cinch--often used with up