• he is seething with anger
• he is seething with anger, to simmer with anger
• burning, ebullient, fervent, fervid, heated, hot, scalding
• to boil, to engineer, to seethe
• boil, fermentation, font, fount, fountain, fund, mint, mother, parent, resource, rise, root, seethe, source, spring, well
• ebullience, ebulliency, ferment, fermentation, outbreak, riot
• to be up to some hanky-panky