WordWeb Online

1. Marked by extreme and violent energy
   "a furious battle";
   - ferocious, fierce, savage
    
2. Marked by extreme anger
   "furious about the accident"; "a furious scowl";
   - angered, enraged, infuriated, maddened, ropable [Austral, NZ], ropeable [Austral, NZ]
    
3. (of the elements) as if showing violent anger
   "furious winds";
   - angry, raging, tempestuous, wild
    
4. Feeling or showing extreme anger
   "wilful stupidity makes him absolutely furious";
   - irate, ireful, steaming [informal], fuming, seething, hopping mad [informal], apoplectic [informal], livid

See also: angry, cross, procellous [archaic], stormy, violent

Encyclopedia: Furious