A firm hold or something easy to accomplish.
Derived from the Spanish word 'cincha' for a saddle girth, it originally referred to the strap used to secure a saddle. In American English, it evolved into a slang term for a certainty or an easy task. It is now occasionally used as a rugged, Western-inspired name.
Less common today
Cinch isn't in the latest US Top 1000. It last peaked at #4,839 in 2012.
US births per 5-year period, 1990βpresent (SSA data).