sepulture vs entombment

sepulture and entombment both are nouns.

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

As nouns, sepulture and entombment are synonyms defined as:

Other synonyms of sepulture include burial, inhumation, interment.

sepulture (noun)	entombment (noun)
a chamber that is used as a grave	the ritual placing of a corpse in a grave
the ritual placing of a corpse in a grave