know it all[noun]Synonyms: smart aleck, *smartass, smarty, smarty-pants, wiseacre, wisecracker, wise guy, wisehead, wisenheimer
[TahlilGaran] English Synonym Dictionary ▲
ˈknow-it-all noun [countable] especially American English informal someone who behaves as if they know everything – used to show disapproval
Synonym : know-all British English [TahlilGaran] Dictionary of Contemporary English ▲
know it all n. A person who acts as if he knows all about everything; someone who thinks no one can tell him anything new.
After George was elected as class president, he wouldn't take suggestions from anyone; he became a know-it-all. ■ Also used like an adjective.
The other students didn't like George's know-it-all attitude. [TahlilGaran] English Idioms Dictionary ▲