adj

• (dated) Causing fear or horror; appalling, terrible.
  "There was an air of gravity and importance about the garb of the person, and something indescribably odd, I might say awful, in the perfect, stonelike stillness of the figure, that effectually checked the testy comment which had at once risen to the lips of the irritated artist."
• (now rare) Awe-inspiring; filling with profound reverence or respect; profoundly impressive.
  "As I am seen could I but gaze on Thee / Awful in majesty and royal might"
• (now rare) Struck or filled with awe or reverence.
  "She spoke about Mr. Pendennis (a worthy little gentleman enough, but there are others as good as he) with an awful reverence, as if he had been the Pope of Rome on his throne, and she a cardinal kneeling at his feet, and giving him incense."
• (obsolete) Terror-stricken.

adv

• (US, Canada) Very, extremely.
  "That's an awful big house."

noun

• (US, neologism, politics, social media) Initialism of affluent white female urban liberal.
  "She's AWFUL... Affluent White Female Urban Liberal."