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

See also: angry, furiously, furiousness, fury, stormy, violent

Encyclopedia: Furious