spook vs ghost

spook and ghost both are nouns.

Word	Noun	Adjective	Verb	Adverb
spook	Yes	No	Yes	No
ghost	Yes	No	Yes	No

As nouns, spook and ghost are synonyms defined as:

Other synonyms of spook include shade, specter, spectre, wraith.

spook (noun)	ghost (noun)
a mental representation of some haunting experience	a mental representation of some haunting experience
someone unpleasantly strange or eccentric	a suggestion of some quality
	the visible disembodied soul of a dead person
	a writer who gives the credit of authorship to someone else

spook (verb)	ghost (verb)
frighten or scare, and often provoke into a violent action	write for someone else
	haunt like a ghost; pursue
	move like a ghost