English

Verb

act up

1. (intransitive, idiomatic) To misbehave; to cause trouble.

   My allergies act up during hay fever season.

   Children may act up in class in an effort to get attention.

1. (intransitive, idiomatic) To perform the duties of an appointment senior to that actually held; to deputise for a superior.

Synonyms

• (misbehave): carry on

See also

• act up to
• throw a tantrum