Definitions:

1. Describes an action done in a petulant, irritable, or childishly bad-tempered manner. ADVERB
   • She pettishly refused to speak to anyone after not getting her way.
2. Implies someone is behaving with sulky annoyance or touchiness, often over something trivial. ADVERB
   • He pettishly dismissed the suggestion without giving it real thought.

Synonyms:

• crossly
• fretfully
• irritably
• petulantly
• sulkily
• testily