A tight girth. Hence an advantage over the one cinched. Sp. cincha.
1872. I leaned down and felt of the cinch, to see if it had slipped.C. King, Sierra Nevada, p. 119. (N.E.D.)
1888. The saddle was also secured by a cinch or girth of cows-hair, which hard riders found a great help in keeping the saddle firm.Mrs. Custer, Tenting on the Plains, p. 212.
1888. Black and blue thinks the Dwyers have a cinch on both the great events.Daily Inter-Ocean, Feb. 2 (Farmer).
1909. You have a cinch such as no man ever possessed.Chicago Evening Post, Feb.