WordWeb Online

1. Be noisy with activity
   - hum, buzz
    
2. Be in an agitated emotional state
   "The customer was seething with anger"
   - boil
    
3. Foam as if boiling
   "a seething liquid"
    
4. Boil vigorously
   "The liquid was seething"
   - roll

Derived forms: seethes, seething, seethed

Type of: be, boil, churn, effervesce, fizz, foam, form bubbles, froth, moil [N. Amer], roil, sparkle