selfish vs self-seeking

selfish is not a noun while self-seeking is a noun.

Word	Noun	Adjective	Verb	Adverb
selfish	No	Yes	No	No
self-seeking	Yes	Yes	No	No

As adjectives, selfish and self-seeking are synonyms defined as:

selfish and self-seeking: concerned chiefly or only with yourself and your advantage to the exclusion of others

Other synonyms of selfish include egocentric, egoistic, egoistical, self-centered, self-centred, self-serving.

selfish (noun)	self-seeking (noun)
	taking advantage of opportunities without regard for the consequences for others

selfish (adjective)	self-seeking (adjective)
concerned chiefly or only with yourself and your advantage to the exclusion of others	concerned chiefly or only with yourself and your advantage to the exclusion of others