surplusage vs overabundance

surplusage and overabundance both are nouns.

Word	Noun	Adjective	Verb	Adverb
surplusage	Yes	No	No	No
overabundance	Yes	No	No	No

As nouns, overabundance is a hypernym of surplusage; that is, overabundance is a word with a broader meaning than surplusage:

Other hypernyms of surplusage include overmuch, overmuchness, superabundance.

surplusage (noun)	overabundance (noun)
a quantity much larger than is needed	a quantity that is more than what is appropriate
	the state of being more than full