Answer: WISENHEIMER

AnswerCrossword Clue
WISENHEIMERKnow-it-all
WISENHEIMERHe knows it all
WISENHEIMERUpstart who makes insolent comments
WISENHEIMERSmart aleck
wisenheimerA person who behaves in an irritatingly smug or arrogant fashion, typically by making clever remarks and displaying their knowledge
wisenheimera smart aleck also WEISENHEIMER
wisenheimera wiseacre or smart aleck.