A mutiny is when sailors, soldiers, or other people under someone's command refuse to obey orders and rebel against their leader. When a ship's crew commits mutiny, they might lock the captain in his cabin and take control of the vessel themselves. When soldiers mutiny, they refuse to follow their commanding officer's orders and may even overthrow that officer.

The word carries serious weight because mutiny means organized rebellion by people who are supposed to follow orders. It goes far beyond simply disagreeing with a boss or arguing with a teacher. In naval and military settings, mutiny has historically been considered one of the gravest offenses, sometimes punishable by death, because it threatens the entire chain of command that keeps a ship or military unit functioning.

The most famous mutiny in history might be the Mutiny on the Bounty in 1789, when the crew of HMS Bounty overthrew their harsh captain, William Bligh, and set him adrift in a small boat in the Pacific Ocean. People still study this mutiny today, debating whether the crew had good reasons for their rebellion or whether they should have endured their captain's strict discipline.

The word can also be used more playfully. If your soccer team jokingly refuses to run the extra laps your coach assigned, someone might call it a “mutiny,” though that's obviously very different from an actual mutiny aboard a ship at sea.