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megalomaniac

American  
[meg-uh-loh-mey-nee-ak] / ˌmɛg ə loʊˈmeɪ niˌæk /

noun

  1. a person who has megalomania.


adjective

  1. Also megalomaniacal megalomanic of, relating to, or suggesting megalomania or a person with it.

Etymology

Origin of megalomaniac

First recorded in 1885–90; megalo- + maniac

Explanation

If you seriously think you’re the only person smart enough to solve the financial crisis, and you demand to be put in charge, people will think you’re a megalomaniac. A megalomaniac is a pathological egotist, that is, someone with a psychological disorder with symptoms like delusions of grandeur and an obsession with power. We also use the word megalomaniac more informally for people who behave as if they're convinced of their absolute power and greatness. Your garden-variety egomaniac might be self-centered and overconfident but he's a little softy compared with the megalomaniac who wants to control the world.

Keep Reading on Vocabulary.com

Vocabulary lists containing megalomaniac

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

“The Happy Dictator,” released as the lead single in September, parodies megalomaniac Saparmurat Niyazov’s approach to governing in Turkmenistan.

From Los Angeles Times • Feb. 27, 2026

Numerous media stories have portrayed Mbappe as something close to a megalomaniac, accused of wielding influence over PSG's tactics and transfer decisions.

From BBC • May 29, 2024

Where critics see an erratic megalomaniac, fans see a visionary working toward our long-term survival.

From Seattle Times • Dec. 8, 2023

He also continued with his megalomaniac delusions and lies, telling Carlson that the court officials cried and apologized to him when he was arrested and arraigned in New York.

From Salon • Apr. 20, 2023

Talent contests and megalomaniac record producers have always paired ingenue wannabes with experienced songwriters, for instance, cashing in quickly on success before the public's appetite for novelty fades.

From "The Story of Music" by Howard Goodall