形容詞petulant とgrouchy

The terms "petulant" and "grouchy" both describe someone who is easily annoyed. 

Petulant: This adjective often implies a childlike or unreasonable irritability. It describes someone who is easily annoyed and complains in a rude or childish manner. The term suggests a more extreme or exaggerated form of irritability, often associated with immature behavior. 

Grouchy: This term describes someone who is easily annoyed and frequently complains, but it does not necessarily carry the same connotation of childishness as "petulant." It is more commonly used in informal contexts to describe general irritability or grumpiness.