WordWeb Online

1. Marked by the exercise of good judgment or common sense in practical matters
   "heady use of one's money";
   - judicious, wise
    
2. Extremely exciting as if by alcohol or a narcotic
   - intoxicating
    
3. Marked by defiant disregard for danger or consequences
   "heady enough to try to seize the gun from the hijacker";
   - foolhardy, rash, reckless

Derived forms: headier, headiest

See also: bold, exciting, prudent

Encyclopedia: Heady