impertinent UK /ɪmˈpɜː.tɪ.nənt/US /ɪmˈpɝ.tɪ.nənt/adjective 2noun 1forms 3 adjective2 •Insolent, ill-mannered or disrespectful; Disregardful. •(no longer used) Not pertaining or related to (something or someone); Irrelevant or useless.Curious speculations, and the contemplation of things that are impertinent to us, and do not concern us, nor serve to promote our happiness, are but a more specious and ingenious sort of idleness — 1664 noun1 •An impertinent individual.Get near fat Mr. Dutton, and behind the screen of his prodigious elbow, you will be comfortably recessed from curious impertinents. — 1808 formsimpertinents · more impertinent · most impertinent