Word Origin & History
cinch1859, Amer.Eng., "saddle-girth," from Sp. cincha "girdle," from L. cingulum "a girdle," from cingere "to surround, encircle," from PIE base *kenk- "to gird, encircle." Sense of "an easy thing" is 1898, via notion of "a sure hold" (1888). The verb is first recorded 1866.