Petulant means childishly irritable or bad-tempered, especially when you don't get your way. When someone acts petulant, they're sulky, whiny, and unreasonably annoyed about something small.

Picture a teammate who pouts and complains when the coach assigns them a different position, or a friend who gives everyone the silent treatment because they didn't win a game. That's petulant behavior: reacting with exaggerated grumpiness and immature irritation that makes others uncomfortable, far beyond normal disappointment or frustration.

Adults can be petulant too. A petulant customer might snap at a store clerk over a minor inconvenience, or a petulant driver might honk angrily the instant a light turns green. The word suggests someone is acting younger than their age, throwing what amounts to a mini tantrum.

When you feel genuinely wronged, standing up for yourself makes sense. But petulant describes that whiny, bratty reaction to not getting exactly what you want, exactly when you want it.