form-only vs formal

form-only is not a noun while formal is a noun.

Word	Noun	Adjective	Verb	Adverb
form-only	No	Yes	No	No
formal	Yes	Yes	No	No

form-only (noun)	formal (noun)
	a gown for evening wear
	a lavish dance requiring formal attire

form-only (adjective)	formal (adjective)
being a matter of form only; lacking substance	being in accord with established forms and conventions and requirements (as e.g. of formal dress)
	(of spoken and written language) adhering to traditional standards of correctness and without casual, contracted, and colloquial forms
	refined or imposing in manner or appearance; befitting a royal court
	logically deductive
	represented in simplified or symbolic form
	characteristic of or befitting a person in authority