spectre vs apparition

spectre and apparition both are nouns.

Word	Noun	Adjective	Verb	Adverb
spectre	Yes	No	No	No
apparition	Yes	No	No	No

As nouns, apparition is a hypernym of spectre; that is, apparition is a word with a broader meaning than spectre:

Other hypernyms of spectre include fantasm, phantasm, phantasma, phantom, shadow.

As nouns, spectre and apparition are synonyms defined as:

Other synonyms of spectre include fantasm, phantasm, phantasma, phantom, specter.

spectre (noun)	apparition (noun)
a mental representation of some haunting experience	an act of appearing or becoming visible unexpectedly
a ghostly appearing figure	something existing in perception only
	the appearance of a ghostlike figure
	a ghostly appearing figure