seethe
     v 1: be noisy with activity; "This office is buzzing with
          activity" [syn: {hum}, {buzz}]
     2: be in an agitated emotional state; "The customer was
        seething with anger" [syn: {boil}]
     3: foam as if boiling; "a seething liquid"
     4: boil vigorously; "The liquid was seething"; "The water
        rolled" [syn: {roll}]
Source: WordNet® 2.0