mastermind
Americanverb (used with object)
noun
verb
noun
Etymology
Origin of mastermind
Explanation
A mastermind is a brilliant thinker with original ideas. You might be a chess mastermind or a criminal mastermind: either way, people will not want to oppose you. Inventors, intellectuals, and famous geniuses call all be called masterminds, from Albert Einstein to theoretical physicist Dr. Shirley Jackson. You could also call people who are successful in their fields — especially if they come up with new ways of doing things — masterminds. Even a brilliant jewel thief might be called a safe-cracking mastermind. As a verb, to mastermind is to act as the leader of some complex plan or scheme.
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.
Over the course of the war, Israel has claimed responsibility for the assassinations of several Hamas leaders, including Yahya Sinwar, widely regarded as a mastermind of the October 7 attack.
From Barron's • May 16, 2026
Jho Low, alleged mastermind of the 1MDB fraud, is seeking a pardon from President Trump to remove U.S. criminal charges.
From The Wall Street Journal • May 12, 2026
Halperin’s accusers were gobsmacked to see Kelly, who’d once given them a sympathetic platform on the Today show, turn around and mastermind his comeback.
From Slate • May 6, 2026
Lee, who died in 2015, is often credited as being the mastermind of Singapore's post colonial transformation from a resource-scarce island to one of Asia's most advanced economies.
From BBC • Apr. 9, 2026
Uncle Brian made a face like an evil mastermind announcing his plan for world domination.
From "Black Swan Green" by David Mitchell
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Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023
Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.