ghastful

adjective2

1. •
   (no longer used) Causing fear; terrifying.

   • Very desolate was that valley, having a dark aspect and a ghastful, such as a man might look for in the infernal glens of Pyriphlegethon or Acheron. — 1922
2. •
   (no longer used) Terrified, frightened.

   • Th' Almighty answers — "I my self will place "The dreadful Stains of Murther on the Face, "That all may shun thy Crimes and Fate. — He said, The Caitiff heard, with ghastful Looks he fled. — 1716