"Grouchy" is an adjective used to describe someone who is irritable or easily annoyed. A grouchy person often displays a sour mood and may complain frequently. This behavior can stem from various factors, such as stress, fatigue, or personal issues. In popular culture, characters like Oscar the Grouch from Sesame Street exemplify this trait. Oscar is known for his grumpy demeanor and love for trash, which adds humor to his character. While being grouchy can be seen as negative, it can also be a relatable human experience that many people encounter at times.