adjective: Bad-tempered; cranky.
[From Latin petere (to seek, assail). Ultimately from the Indo-European root pet- (to rush or fly), which also gave us feather, petition, compete, perpetual, propitious, pteridology, pinnate, and lepidopterology. Earliest documented use: 1598.
"Idol, like the petulant child who can't understand that her antics have ceased to be entertaining, kept trying to sell it."