disgruntle

To disgruntle means to make someone dissatisfied, discontented, or sulky—essentially to put them in a bad mood or upset them. For example: "The sudden policy change disgruntled the entire department," or "Poor communication tends to disgruntle customers."

While disgruntle is perfectly correct as a verb, it's actually most commonly encountered as an adjective: disgruntled. When someone is disgruntled, they're unhappy, disappointed, or dissatisfied with a situation. You might read about "disgruntled employees threatening to strike" or hear someone say, "He had the look of a disgruntled commuter stuck in traffic."

The word has a charming linguistic history. It emerged in the 17th century from the prefix "dis-" (expressing negation or reversal) combined with "gruntle," an archaic word meaning to grumble or make grunting sounds. What makes this particularly amusing is that "gruntle" as a standalone verb meaning "to please" or "to put in good humor" actually came later—created humorously as the opposite of disgruntle! It's one of those rare cases where the negative form came first.

So when you disgruntle someone, you're essentially removing their contentment and leaving them grumpy, dissatisfied, or resentful. And if you ever want to sound playfully clever, you can talk about trying to "gruntle" the disgruntled!