Seething means being extremely angry but holding it inside, like a pot of water that's boiling so hard it's about to overflow. When you're seething, you're not yelling or throwing things. Instead, the anger is churning around inside you, intense and barely controlled.

You might be seething after someone takes credit for your work in class, or when a friend breaks a promise for the third time. Your face might stay calm, but inside you feel hot and furious. The word captures that specific kind of anger that's simmering just below the surface, ready to burst out.

The word comes from an old term for boiling, which perfectly describes the feeling: like something's bubbling and roiling inside you. When a crowd is seething with anger, you can sense the tension even if nobody's shouting yet.

People sometimes confuse seething with just being annoyed or frustrated, but seething is much more intense. It's closer to furious than irritated. If your little brother hides your homework, you might be annoyed. If he does it right before a major presentation you've worked on for weeks, you might be seething.