1. past tense of cinch; to fasten or tighten a cinch (a belt or strap around a horse's body)
Usage: equestrian; often used with horses and saddles
2. past tense of cinch; to make certain or secure; to guarantee or ensure
Usage: informal

Examples

• She chinched the saddle tightly before mounting the horse.
• He chinched the deal by signing the contract yesterday.
• The cowboy chinched his horse's saddle before the long ride.
• That victory chinched their place in the playoffs.
• She chinched the rope around the bundle to keep it secure.