Verb – Seethe
1 : to feel or show strong emotion (such as anger) even though you try to control it
He seethed at his brother’s success.
— often + with
He seethed with anger/jealousy.
The letter seethes with resentment.
a seething letter
2 : to be in a state of constant activity
We found ourselves in the middle of a seething crowd.
— often used as (be) seething with
The island is seething with tourists. (=there are very many tourists moving around on the island)
The field was seething with crickets.
His brain was seething with ideas.