Intolerable means impossible to bear or endure. When something is intolerable, it's so unpleasant, painful, or wrong that you simply cannot accept it or live with it any longer.

If you can tolerate your little brother's loud music for a while, it becomes intolerable when he plays it at full volume for three hours straight and you can't concentrate on your homework or think clearly.

Conditions can be intolerable: intolerable heat that makes you feel sick, intolerable noise that prevents you from sleeping, or intolerable pain that requires immediate medical attention. Situations can be intolerable too: being treated unfairly day after day might become intolerable, pushing someone to finally speak up or make a change.

Throughout history, people have called certain conditions intolerable when demanding change. American colonists declared British rule intolerable. Workers have called dangerous factory conditions intolerable. When something crosses from merely difficult to truly intolerable, it signals a breaking point where action becomes necessary. The word carries weight because it means you've reached your absolute limit.