WordWeb Online

1. Roused to anger
   "she gets mad when you wake her up so early"; "mad at his friend";
   - huffy, sore
    
2. Affected with madness or insanity
   "a man who had gone mad";
   - brainsick, crazy, demented, disturbed, sick, unbalanced, unhinged
    
3. Marked by uncontrolled excitement or emotion
   "a mad whirl of pleasure";
   - delirious, excited, frantic, unrestrained
    
4. Very foolish
   "a completely mad scheme to build a bridge between two mountains";
   - harebrained, insane

Derived forms: madder, maddest

See also: angry, daft, dumb, foolish, insane, stupid, wild

Encyclopedia: Mad, Bad, and Dangerous to Know Mad Mad, Bad and Dangerous to Know Mad, Bad and Dangerous