singular form vs word form

singular form and word form both are nouns.

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

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

singular form: the form of a word that is used to denote a singleton
word form: the phonological or orthographic sound or appearance of a word that can be used to describe or identify something

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

singular form (noun)	word form (noun)
the form of a word that is used to denote a singleton	the phonological or orthographic sound or appearance of a word that can be used to describe or identify something