tightens

1.收紧,拉紧,抽紧;绷紧;固定

1.to turn something such as a screw or a cover until it is tight and you cannot turn it any more

2.to pull something such as a rope or a belt until it is straighter or until it fits more tightly around something; if something such as a rope or a chain tightens, it becomes straighter or it fits more tightly around something

3.if your hand tightens, or if your fingers tighten, you hold something more tightly

4.if a muscle or a part of your body tightens, or if you tighten it, it becomes hard and stiff, often because you are angry or afraid; if your mouth tightens, or if your lips tighten, your mouth looks narrow because you are angry or annoyed

5.to make a set of rules stricter or harder to avoid; to make an arrangement for guarding or protecting something more effectively