Synonyms for Self-importance:

n.

bighead, self-love, egoism, snobbery, arrogance, narcissism, bigheadedness, condescension. conceit (noun)
ego, egoism.
pride (noun)
arrogance.
self-importance (noun)
egotism, swelled head, ego.

Other synonyms:

condescension, narcissism, snobbery, bighead, bigheadedness. egoism. Other relevant words:
bighead, self-love, egoism, snobbery, arrogance, narcissism, bigheadedness, condescension.