WordWeb Online

1. An informal form of address for a man
   "Say, dude, what are you doing?";
   - fellow, buster [informal], cock [Brit, informal], bruv [UK, informal], bo [US, informal], matey [Brit, informal], bro [US, informal]
    
2. A man who is much concerned with his dress and appearance
   - dandy, fop, gallant [archaic], beau [archaic], swell [informal], fashion plate, clotheshorse [informal]

Derived forms: dudes

Type of: adult male, bozo [N. Amer, informal], cat [N. Amer, informal], chappie [Brit, informal], geezer [Brit, informal], guy [informal], hombre [Brit, N. Amer, informal], man, sod [informal]

Encyclopedia: Dude, You're Screwed