To behave deceitfully or hypocritically; to dissemble.
act up
To misbehave; to cause trouble.
act one's age
To behave in a manner appropriate to one's age.
act out
To perform something specific.
act of Congress
An authorization that is extremely difficult to obtain, especially in …
act one's age, not one's shoe size
Synonym of act one's age (“to behave in a mature manner; to avoid bein…