egoism vs self-centeredness

egoism and self-centeredness both are nouns.

Word	Noun	Adjective	Verb	Adverb
egoism	Yes	No	No	No
self-centeredness	Yes	No	No	No

As nouns, egoism and self-centeredness are synonyms defined as:

egoism and self-centeredness: concern for your own interests and welfare

Other synonyms of egoism include egocentrism, self-concern, self-interest.

egoism (noun)	self-centeredness (noun)
concern for your own interests and welfare	concern for your own interests and welfare
(ethics) the theory that the pursuit of your own welfare is the basis of morality