verb
seethe
SEETHE/siːð/
To feel intense anger while showing little of it.
The adult seethes quietly, clenching a fist beneath the table.

Etymology
Boiling and foaming gave a figure for anger churning intensely beneath the surface.
More examples
- He seethes behind a polite smile.
- She leaves the meeting seething with resentment.
Forms
seethe · seethes · seething
Similar words
- fume
- Feel or express strong irritation.
- smolder
- Harbor anger that remains partly concealed.