Awful describes something extremely unpleasant, bad, or shocking in quality or effect. It implies a severe lack of quality, causing distress, fear, or disgust. The intensity of 'awful' often suggests a considerable negative impact, whether it be on one's senses, emotions, or physical well-being.
While sometimes used informally to simply mean 'very' or 'extremely,' its core meaning remains rooted in negativity and displeasure.
GAG BAD
DIRE FOUL VILE AWED
LOUSY DREAD AWING NASTY
HORRID ROTTEN DISMAL
GHASTLY ABYSMAL DIREFUL DREADED FEARFUL PAINFUL AMAZING AWESOME AWFULLY THEPITS
DREADFUL TERRIBLE HORRIBLE GRUESOME FEARSOME HORRIFIC TERRIBLY WRETCHED
APPALLING EXECRABLE ABHORRENT ATROCIOUS FRIGHTFUL
HORRENDOUS ABOMINABLE TREMENDOUS IMPRESSIVE DISGUSTING
REVERENTIAL FRIGHTENING UNSPEAKABLE FRIGHTFULLY UNTHINKABLE
AWEINSPIRING