lunette vs fenestella

lunette and fenestella both are nouns.

Word	Noun	Adjective	Verb	Adverb
lunette	Yes	No	No	No
fenestella	Yes	No	No	No

As nouns, lunette and fenestella are synonyms defined as:

lunette and fenestella: oval or circular opening; to allow light into a dome or vault

lunette (noun)	fenestella (noun)
oval or circular opening; to allow light into a dome or vault	oval or circular opening; to allow light into a dome or vault
temporary fortification like a detached bastion