act up Meaning, definition in Cambridge English Dictionary
Cambridge Dictionaries online Cambridge Dictionaries online

The most popular online dictionary and thesaurus for learners of English

Meaning of "act up" - English Dictionary

See all translations

act up

phrasal verb with act uk   us   /ækt/ verb
If a person, especially a child, acts up, they behave badly: Sophie got bored and started acting up. If a machine or part of the body acts up, it does not perform as well as it should: My car always acts up in cold weather. Her shoulder was acting up (= hurting because of injury).
(Definition of act up from the Cambridge Advanced Learners Dictionary & Thesaurus © Cambridge University Press)
What is the pronunciation of act up?
Add Cambridge dictionaries to your browser to your website

Definitions of “act up” in other dictionaries

Word of the Day
stretch the truth

to say something that is not completely honest in order to make someone or something seem better than it really is

Word of the Day

July 4th, Bastille Day, and the language of revolution.
July 4th, Bastille Day, and the language of revolution.
by Liz Walter,
July 01, 2015
With America’s Independence Day on the 4th and France’s Bastille Day on the 14th, July certainly has a revolutionary theme, so this blog looks at words and phrases we use to talk about the dramatic and nation-changing events that these days celebrate. In particular, it focuses on one of the most important

Read More 

generation pause noun
generation pause noun
July 06, 2015
informal young adults who are not able to do things previously typical for their age group such as buy a home or start a family because of lack of money Meanwhile, a new study released last week revealed a quarter of Brits believe they’ll never own a property, leading them to be

Read More