The Collaborative International Dictionary of English v.0.48:
Petulantly \Pet"u*lant*ly\, adv. In a petulant manner. [1913 Webster]WordNet (r) 3.0 (2006):
petulantly adv 1: in a petulant manner; "he said testily; `Go away!'" [syn: testily, irritably, petulantly, pettishly]