louvre vs spline

louvre and spline both are nouns.

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

As nouns, spline is a hypernym of louvre; that is, spline is a word with a broader meaning than louvre:

louvre: one of a set of parallel slats in a door or window to admit air and reject rain
spline: a thin strip (wood or metal)

Other hypernyms of louvre include slat.

louvre (noun)	spline (noun)
one of a set of parallel slats in a door or window to admit air and reject rain	a thin strip (wood or metal)
	a flexible strip (wood or rubber) used in drawing curved lines