pelmet vs valance board

pelmet and valance board both are nouns.

Word	Noun	Adjective	Verb	Adverb
pelmet	Yes	No	No	No
valance board	Yes	No	No	No

As nouns, pelmet and valance board are synonyms defined as:

pelmet and valance board: a decorative framework to conceal curtain fixtures at the top of a window casing

Other synonyms of pelmet include cornice, valance.

pelmet (noun)	valance board (noun)
a decorative framework to conceal curtain fixtures at the top of a window casing	a decorative framework to conceal curtain fixtures at the top of a window casing