Dyspeptic describes someone who is grumpy, irritable, and complains a lot, like they're in a perpetually bad mood. A dyspeptic person might grumble about the weather, criticize everyone's ideas, and find something wrong with everything. Think of that character in stories who scowls at children playing too loudly or mutters that “things were better in my day.”

The word comes from a medical condition called dyspepsia, which means indigestion or an upset stomach. Imagine how cranky you feel when your stomach hurts: nothing seems quite right, and little annoyances bother you more than usual. That's the connection. Over time, people started using dyspeptic to describe anyone who acts chronically grouchy, whether their stomach actually hurts or not.

You might encounter a dyspeptic character in a novel, someone whose sour outlook contrasts with happier characters around them. A dyspeptic relative might complain about the music at a family gathering, the temperature of the room, and how dinner was cooked, all in the same evening. The word captures that particular brand of chronic, grumbling dissatisfaction.