seethe

To seethe is to be filled with intense, often suppressed, anger or resentment. Think of a pot of water boiling over a flame; even if the lid is kept on, the liquid inside is churning, bubbling, and building up immense pressure. It describes a state of internal turbulence where someone is vibrating with fury but might not yet be expressing it openly. While it can describe literal bubbling, like a stormy sea or boiling liquid, it is most frequently used to describe a person’s emotional state. It implies a "slow burn" rather than a sudden explosion. You will often hear it used with the preposition "with," such as "seething with rage" or "seething with indignation," emphasizing that the emotion is consuming the person from the inside out.
In conversation
Discussing a workplace issue
Did you see Mark's face when the boss gave his project to the intern?
Did you see Mark's face when the boss gave his project to the intern?
Yeah, he was absolutely seething. I thought he might walk out.
Yeah, he was absolutely seething. I thought he might walk out.
Used here to describe a visible, intense, but controlled anger.
A tense family dinner
Everything okay? You've been quiet all evening.
Everything okay? You've been quiet all evening.
I'm fine, Mom. Just seething over that parking ticket I got earlier.
I'm fine, Mom. Just seething over that parking ticket I got earlier.
Highlights how someone can be preoccupied by an anger-inducing event.
Examples
The soup began to seethe in the pot.
The soup began to seethe in the pot.
She seethed with frustration after the meeting.
She seethed with frustration after the meeting.
Beneath his calm exterior, he was seething at the injustice of the situation.
Beneath his calm exterior, he was seething at the injustice of the situation.