Answer: knowitall

AnswerCrossword Clue
KNOWITALL

Wisenheimer

KNOWITALL

Smart aleck

KNOWITALL

Advice ignorer

KNOWITALL
Would-be expert
KNOWITALL
Smarty-pants
KNOWITALLSmart aleck, say
KNOWITALLAdvice-disdaining sort
KNOWITALLOne needing no advice