Grumpy describes someone who is irritable, cranky, and easily annoyed, often for no obvious reason. A grumpy person might snap at small things, complain about minor problems, or just seem generally unhappy with everything around them.

You've probably noticed that people often get grumpy when they're tired, hungry, or not feeling well. Your dad might be grumpy before his morning coffee. Your friend might turn grumpy after staying up too late. Even the friendliest person can become temporarily grumpy when circumstances wear them down.

Some characters, like Oscar the Grouch or Carl Fredricksen from Up, seem permanently grumpy. They scowl, grumble, and act annoyed by cheerful people and sunny days. But even chronically grumpy people usually have reasons for their disposition, and they may turn out to have kind hearts underneath their crusty exterior.

When someone calls you grumpy, they're usually noticing that you're being more negative and irritable than usual. Sometimes realizing you're being grumpy helps you snap out of it, especially if you figure out what's actually bothering you.