perilune vs periapsis

perilune and periapsis both are nouns.

Word	Noun	Adjective	Verb	Adverb
perilune	Yes	No	No	No
periapsis	Yes	No	No	No

As nouns, periapsis is a hypernym of perilune; that is, periapsis is a word with a broader meaning than perilune:

perilune: periapsis in orbit around the moon
periapsis: (astronomy) the point in an orbit closest to the body being orbited

Other hypernyms of perilune include point of periapsis.

perilune (noun)	periapsis (noun)
periapsis in orbit around the moon	(astronomy) the point in an orbit closest to the body being orbited