Definitions
There are 2 meanings of the phrase
Act Up.
Act Up - as a verb
Misbehave badly; act in a silly or improper way
Example: "The children acted up when they were not bored"
Make itself felt as a recurring pain
Example: "My arthritis is acting up again"
Example Sentences
"My computer tends to act up whenever I have multiple programs running at once."
"The children always act up when they're tired."
"The weatherman predicted that the storm would act up later tonight."
