Having refused what I considered an impertinent request, I could see that my personal safety was in jeopardy.
No doubt it would have felt strange, impertinent even, but after all it had been common knowledge that Dumbledore had taken part in that legendary duel with Grindelwald, and Harry had not thought to ask Dumbledore what that had been like, nor about any of his other famous achievements.
He venerated Snape, the first Slytherin headmaster since he himself had controlled the school, and they had to be careful not to criticize or ask impertinent questions about Snape, or Phineas Nigellus would instantly leave his painting.
"— mediocre, arrogant as his father, a determined rule-breaker, delighted to find himself famous, attention-seeking and impertinent — " "You see what you expect to see, Severus," said Dumbledore, without raising his eyes from a copy of Transfiguration Today.
There are no more uses of "impertinent" in the book.
Show samples from other sources
It was impertinent of the child to lecture a grownup.
He deemed all such inquiries on the part of a slave improper and impertinent, and evidence of a restless spirit.
Douglass, Frederick -- Narrative of the Life of Frederick Douglass An American Slave