noun

the fact of being excessively conceited or absorbed in oneself.

in his arrogance and egotism, he underestimated Gill

self-centredness,egocentricity,egomania,self-interest,selfishness,self-seeking,self-serving,self-regard,self-absorption,self-obsession,self-love,narcissism,self-admiration,self-adulation,vanity,conceit,conceitedness,self-conceit,pride,self-esteem,self-importance,boastfulness,boasting,bragging,blowing one’s own trumpet,amour propre,looking after number one,braggadocio