apsis vs apse

apsis and apse both are nouns.

Word	Noun	Adjective	Verb	Adverb
apsis	Yes	No	No	No
apse	Yes	No	No	No

As nouns, apsis and apse are synonyms defined as:

apsis and apse: a domed or vaulted recess or projection on a building especially the east end of a church; usually contains the altar

apsis (noun)	apse (noun)
a domed or vaulted recess or projection on a building especially the east end of a church; usually contains the altar	a domed or vaulted recess or projection on a building especially the east end of a church; usually contains the altar