WordWeb Online

1. Exceptionally bad or displeasing
   "an awful voice";
   - atrocious, abominable, dreadful, painful, terrible, unspeakable, horrible
    
2. Offensive or even (of persons) malicious
   - nasty
    
3. Causing fear, dread or terror
   "the awful war"; "an awful risk";
   - dire, direful, dread, dreaded, dreadful, fearful, fearsome, frightening, horrendous, horrific, terrible
    
4. Inspired by a feeling of fearful wonderment or reverence
   "awful worshippers with bowed heads";
   - awed
    
5. Extreme in degree, extent, amount or impact
   - frightful, terrible, tremendous
    
6. [archaic] Inspiring awe, admiration or wonder
   "this sea, whose gently awful stirrings seem to speak of some hidden soul beneath";
   - amazing, awe-inspiring, awesome, awing, breathtaking

1. Used as an intensifier
   "I'm awful sorry";
   - terribly, awfully, frightfully, execrably, appallingly

See also: alarming, bad, cruddy [informal], dirty, extraordinary, filthy, grotty [Brit, informal], hateful, impressive, lousy [informal], mean, nastiness, reverent, unpleasant

Encyclopedia: Awful, Beautiful Life