funeral vs entombment

funeral and entombment both are nouns.

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

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

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

funeral (noun)	entombment (noun)
a ceremony at which a dead person is buried or cremated	the ritual placing of a corpse in a grave