excess vs extraneity

excess and extraneity both are nouns.

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

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

excess: immoderation as a consequence of going beyond sufficient or permitted limits
extraneity: The state of not forming an essential or vital part.

excess (noun)	extraneity (noun)
excessive indulgence	The state of not forming an essential or vital part.
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)	extraneity (adjective)
more than is needed, desired, or required