Meanings
How to pronounce "act up":
AU
To misbehave; to cause trouble.
Example: "My allergies act up during hay fever season."
Example: "Children may act up in class in an effort to get attention."
To perform the duties of an appointment senior to that actually held; to deputise for a superior. (Can we add an example for this sense?)
Example: "Acting up is always recommended when you find yourself under a new boss."
Example Sentences
1
I can't concentrate when my allergies act up.
