megalomaniac

 
Pronunciation: /mɛɡələˈmeɪniak/

noun

  • a person who has an obsessive desire for power.
  • a person who suffers delusions of their own power or importance.

adjective

  • exhibiting megalomania.

Derivatives

megalomaniacal

Pronunciation: /-məˈnʌɪək(ə)l/
adjective