To detest means to hate something or someone intensely. It's a strong word that goes beyond simple dislike. When you detest Brussels sprouts, you don't just prefer not to eat them: you can't stand them. When someone detests dishonesty, they feel genuine anger and disgust when they encounter lying or cheating.

The word carries a sense of deep revulsion or loathing. You might dislike doing chores, but you detest being falsely accused of something you didn't do. A person might dislike rainy days but detest cruelty to animals. The intensity matters: detesting something means it bothers you at a gut level.

You'll often see detest used for things people find morally wrong or personally unbearable. A character in a novel might detest the villain who betrayed her family. A historical figure might have detested injustice and dedicated their life to fighting it. Notice that while you might casually say you “hate” broccoli, using detest suggests something that truly repels you, something you'd go out of your way to avoid.