plural vs castanets

plural and castanets both are nouns.

Word	Noun	Adjective	Verb	Adverb
plural	Yes	Yes	No	No
castanets	Yes	No	No	No

plural (noun)	castanets (noun)
the form of a word that is used to denote more than one	(used in the plural) a percussion instrument consisting of a pair of hollow pieces of wood or bone (usually held between the thumb and fingers) that are made to click together (as by Spanish dancers) in rhythm with the dance

plural (adjective)	castanets (adjective)
grammatical number category referring to two or more items or units
composed of more than one member, set, or kind