megalomania

/ˌmɛɡəloʊˈmeɪniə/
noun
  1. A mental condition in which a person has an exaggerated sense of their own power, importance, or abilities; often used figuratively to describe extreme ambition or arrogance.
    • His megalomania made it impossible for him to accept any criticism.
    • The dictator's megalomania led him to believe he could conquer the entire continent.
    • Some historians argue that the emperor's megalomania contributed to the empire's downfall.
Synonyms
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