petulant (adj) – irritable or cranky, often in a childish way
BREAKDOWN: PET- (strive) + -ANT (inclined to)
— petulance is the state of being petulant
This word is built on the root PET-, which means to seek, ask, or strive.
Common PET- words include appetite, competent, competition, petition, and repeat.
More esoteric PET- words include appetent and petulance.