ghostly vs spookish

ghostly

adj
  • Spooky; frightening. 

  • Of or pertaining to ghosts or spirits. 

spookish

adj
  • Frightening or unnerving in the manner of something eerie or supernatural; spooky. 

  • Easily startled, frightened, or unnerved. 

How often have the words ghostly and spookish occurred in a corpus of books? (source: Google Ngram Viewer )