funeral vs sepulture

funeral and sepulture both are nouns.

Word	Noun	Adjective	Verb	Adverb
funeral	Yes	No	No	No
sepulture	Yes	No	No	No

As nouns, sepulture is a hyponym of funeral; that is, sepulture is a word with a more specific, narrower meaning than funeral:

Other hyponyms of funeral include burial, entombment, inhumation, interment, sky burial.

funeral (noun)	sepulture (noun)
a ceremony at which a dead person is buried or cremated	a chamber that is used as a grave
	the ritual placing of a corpse in a grave