tight‧en also tighten up
1 [transitive] to close or fasten something firmly by turning it [≠ 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.
3HBH [intransitive and transitive] to become stiff or make a part of your body become stiff [≠ relax]:
His mouth tightened into a thin, angry line.
Tighten up the muscles of both arms.

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 [≠ relax]:
Efforts to tighten the rules have failed.
tighten up on something
a range of measures to tighten up on illegal share dealing

tighten your belt

informal to try to spend less money than you used to:
Businesses were tightening their belts and cutting jobs.

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.

Dictionary results for "tighten"
Dictionary pictures of the day
Do you know what each of these is called?
What is the word for picture 1? What is the word for picture 2? What is the word for picture 3? What is the word for picture 4?
Click on any of the pictures above to find out what it is called.