plural form vs word form

plural form and word form both are nouns.

Word	Noun	Adjective	Verb	Adverb
plural form	Yes	No	No	No
word form	Yes	No	No	No

As nouns, word form is a hypernym of plural form; that is, word form is a word with a broader meaning than plural form:

plural form: the form of a word that is used to denote more than one
word form: the phonological or orthographic sound or appearance of a word that can be used to describe or identify something

Other hypernyms of plural form include descriptor, form, signifier.

plural form (noun)	word form (noun)
the form of a word that is used to denote more than one	the phonological or orthographic sound or appearance of a word that can be used to describe or identify something