louver vs louvre

louver and louvre both are nouns.

Word	Noun	Adjective	Verb	Adverb
louver	Yes	No	No	No
louvre	Yes	No	No	No

As nouns, louver and louvre are synonyms defined as:

louver and louvre: one of a set of parallel slats in a door or window to admit air and reject rain

Other synonyms of louver include fin.

louver (noun)	louvre (noun)
one of a set of parallel slats in a door or window to admit air and reject rain	one of a set of parallel slats in a door or window to admit air and reject rain