A firm hold or tight grip. The climber had a cinch on the rope, ensuring he wouldn't fall.
A thing that is very easy to do. The exam was a cinch for her because she had studied thoroughly.
A strap that holds a saddle on a horse. Before riding, he checked the cinch to make sure the saddle was secure.
A person or thing that is certain to succeed or happen; a sure bet. With his speed, the horse was a cinch to win the race.