tighten
verb
ˈtaɪtn verb
1 to close or fasten something firmly by turning it 使变紧; 使更牢固; T
Tighten the screws firmly.
把螺丝拧紧。
I’d put the new tyre on, but I hadn’t tightened up the wheel.
我把新轮胎装上了，但没有上紧轮子。
2 if you tighten a rope, wire etc, or if it tightens, it is stretched or pulled so that it becomes tight 绷紧，拉紧 I,T
When you tighten guitar strings, the note gets higher.
你把吉他的弦紧一紧，音就会变高。
The rope tightened around his body.
他身上的绳子绷紧了。
3 to become stiff or make a part of your body become stiff （使）〔身体的某一部分〕变得僵硬，变得僵直; I,T
His mouth tightened into a thin, angry line.
他的嘴抿成了一道细缝，一副生气的样子。
Tighten up the muscles of both arms.
绷紧两臂肌肉。
4
tighten your grip/hold on sth
a. to control a place or situation more strictly b. to hold someone or something more firmly 更紧地抓住〔某人或某物〕
Rebel forces have tightened their hold on the capital.
叛军加强了对首都的控制。
Sarah tightened her grip on my arm.
萨拉把我的手臂抓得更紧了。
5 to make a rule, law, or system more strict 加紧，加强〔规则、法律或制度〕; T
Efforts to tighten the rules have failed.
严格规章制度的努力失败了。
tighten up on sth
a range of measures to tighten up on illegal share dealing
一系列严格控制非法股票交易的措施
6
tighten your belt
to try to spend less money than you used to [非正式] 勒紧裤带，设法更节俭地过日子 informal
Businesses were tightening their belts and cutting jobs.
企业都在勒紧裤带，削减工作岗位。
7
tighten the screws (on sb)
to try to force someone to do something, by threatening them or making things difficult for them – used in news reports [非正式] （对某人）胁迫威逼;（对某人）采取更为严厉的措施〔用于新闻报道〕 informal
Closing the border would tighten the screws on the terrorists.
关闭边境将使恐怖分子受到更为严厉的打击。
8 if a race or competition tightens, the distance between the competitors becomes smaller [美] 〔比赛〕变得激烈 （紧张） I | AmE
He expects the presidential race to tighten.
他预计竞选总统的角逐还会更激烈。
9 if a team or group tightens up, they start working together more effectively 加紧，加强
tighten sth ↔ up
We have tightened up the defence and are winning matches as a result.
我们加强了防守，所以现在比赛我们都是赢的。