ego vs nous

ego and nous both are nouns.

Word	Noun	Adjective	Verb	Adverb
ego	Yes	No	No	No
nous	Yes	No	No	No

As nouns, nous is a hypernym of ego; that is, nous is a word with a broader meaning than ego:

ego: (psychoanalysis) the conscious mind
nous: that which is responsible for one's thoughts, feelings, and conscious brain functions; the seat of the faculty of reason

Other hypernyms of ego include brain, head, mind, psyche.

ego (noun)	nous (noun)
(psychoanalysis) the conscious mind	that which is responsible for one's thoughts, feelings, and conscious brain functions; the seat of the faculty of reason
your consciousness of your own identity	common sense
an inflated feeling of pride in your superiority to others