excess vs exorbitance

excess and exorbitance both are nouns.

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

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

excess: immoderation as a consequence of going beyond sufficient or permitted limits
exorbitance: excessive excess

excess (noun)	exorbitance (noun)
excessive indulgence	excessive 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)	exorbitance (adjective)
more than is needed, desired, or required