superfluous vs excess

superfluous is not a noun while excess is a noun.

Word	Noun	Adjective	Verb	Adverb
superfluous	No	Yes	No	No
excess	Yes	Yes	No	No

As adjectives, superfluous and excess are synonyms defined as:

Other synonyms of superfluous include extra, redundant, spare, supererogatory, supernumerary, surplus.

superfluous (noun)	excess (noun)
	excessive indulgence
	immoderation as a consequence of going beyond sufficient or permitted limits
	a quantity much larger than is needed
	the state of being more than full

superfluous (adjective)	excess (adjective)
more than is needed, desired, or required	more than is needed, desired, or required
serving no useful purpose; having no excuse for being