cinch

今日の単語はThe Running Manに出てきた知っているが意味が分からない "cinch" です。
An inflated blood pressure cuff had been cinched to his right arm. A number of electrodes had been pasted to his head, and wires from both his head and arm were jacked into a console beside the doctor.
"a piece of cake" と一緒に覚えた "cinch" ですが、上の引用個所の"cinch" は動詞で、文脈からすると、恐らく血圧計の血圧バンドが締め付ける状態を示している様ですが、辞書で確認します。
・American Heritage Dictionary:
1. To encircle or wrap tightly: "her hair orderly, her nightgown cinched around her neck" (E. Annie Proulx).
2. To tighten (an encircling cord or belt, for example).
・Oxford English Dictionary: Secure (a garment) with a belt.: I've cinched my belts inward relentlessly, drilling new holes as the slimming down process did its job.
納得ですが、英語は "It's a cinch." とは中々いきません。