Smarty pants American noun phrase
A person who acts as if they are more intelligent than others, or they know everything.
I will humble that smarty pants. His arrogance is intolerable.
Be humble! Stop acting like a smarty pants. There is plenty of things that you don't know.
A person who tries to seem funny and clever by cracking jokes, but such that annoys others.
Stop making jokes, smarty pants. Come and give me a hand!
I just tried to entertain them, but they called me a smarty pants.
This phrase dates from 1920s-1930s. It was first as a schoolyard taunt.