Conceit or vanity: an attitude of overestimating oneself or having excessive pride in one's abilities.
彼は自惚れが強くて、人の助言を聞こうとしない。
He is very conceited and won't listen to others' advice.
自惚れのない態度は周囲から信頼を得やすい。
A lack of conceit makes it easier to gain others' trust.
若い頃の自惚れが原因で大きな失敗をした。
His youthful conceit caused a big failure.