An exaggerated opinion of your own importance WordNet 3.0 & Open English WordNet

Egotism is defined as the drive to maintain and enhance favorable views of oneself and generally features an inflated opinion of one's personal features and importance distinguished by a person's amplified vision of one's self and self-importance. Wikipedia

The drive to maintain and enhance favorable views of oneself Wikipedia Disambiguation

Drive to maintain and enhance favorable views of oneself Wikidata

The tendency to think of self and self-interest. OmegaWiki

An exaggerated estimate of one's own importance or merit, especially as manifested by the conduct or manners; self-conceit. Wiktionary

Exaggerated estimate of one's own importance. Wiktionary (translation)