The Collaborative International Dictionary of English v.0.48:
Pertly \Pert"ly\, adv. In a pert manner. [1913 Webster]WordNet (r) 3.0 (2006):
pertly adv 1: in an impudent or impertinent manner; "a lean, swarthy fellow was peering through the window, grinning impudently" [syn: impertinently, saucily, pertly, freshly, impudently]