tight ‧ en /ˈtaɪtn/ BrE AmE ( also tighten up ) verb
[ Word Family: adverb : ↑ tight , ↑ tightly ; verb : ↑ tighten ; noun : ↑ tightness ; adjective : ↑ tight ]
1 . [transitive] to close or fasten something firmly by turning it OPP loosen :
Tighten the screws firmly.
I’d put the new tyre on, but I hadn’t tightened up the wheel.
2 . [intransitive and transitive] if you tighten a rope, wire etc, or if it tightens, it is stretched or pulled so that it becomes tight:
When you tighten guitar strings, the note gets higher.
The rope tightened around his body.
3 . [intransitive and transitive] to become stiff or make a part of your body become stiff OPP relax :
His mouth tightened into a thin, angry line.
Tighten up the muscles of both arms.
4 . tighten your grip/hold on something
a) to control a place or situation more strictly:
Rebel forces have tightened their hold on the capital.
b) to hold someone or something more firmly:
Sarah tightened her grip on my arm.
5 . [transitive] to make a rule, law, or system more strict OPP relax :
Efforts to tighten the rules have failed.
tighten up on something
a range of measures to tighten up on illegal share dealing
6 . tighten your belt informal to try to spend less money than you used to:
Businesses were tightening their belts and cutting jobs.
7 . tighten the screws (on somebody) informal to try to force someone to do something, by threatening them or making things difficult for them – used in news reports:
Closing the border would tighten the screws on the terrorists.
8 . [intransitive] American English if a race or competition tightens, the distance between the competitors becomes smaller:
He expects the presidential race to tighten.
tighten up phrasal verb
if a team or group tightens up, they start working together more effectively
tighten something ↔ up
We have tightened up the defence and are winning matches as a result.