excess vs superfluity

excess and superfluity both are nouns.

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

As nouns, superfluity is a hyponym of excess; that is, superfluity is a word with a more specific, narrower meaning than excess:

excess: immoderation as a consequence of going beyond sufficient or permitted limits
superfluity: extreme excess

excess (noun)	superfluity (noun)
excessive indulgence	extreme excess
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

excess (adjective)	superfluity (adjective)
more than is needed, desired, or required