overconfidence

American

[oh-ver-kon-fi-duhns] / ˈoʊ vərˈkɒn fɪ dəns /

noun

the quality of having an unrealistically high opinion of one’s own judgment, ability, powers, etc..

Underestimating the enemy can induce laziness and encourage overconfidence.
Psychologists have determined that overconfidence causes people to overestimate their ability to control events and underestimate risks.

Etymology

Origin of overconfidence

over- ( def. ) + confidence ( def. )

Explanation

Overconfidence is what you've got when you're more sure of yourself than you should be. In a chess tournament, overconfidence might lead your opponent to underestimate you — which means you'll take her completely by surprise when you trounce her. Confidence is a good quality. It means you are secure and believe in yourself. Overconfidence, on the other hand, means you feel certain about your abilities or eventual success in situations that are not so clear-cut. Your overconfidence might mean you fail your driving test, for example, because you're so sure you're a great driver that you don't practice parallel parking.

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Vocabulary lists containing overconfidence

Psychology

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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.

When the market mob is too greedy, or too afraid—and that is the essence of a huge move, up or down—options-centric investors look to buy on fear and sell on overconfidence.

From Barron's • Feb. 11, 2026

He also developed what he calls the adaptive markets hypothesis, which uses the principles of evolution to explain behaviors such as loss aversion and overconfidence.

From The Wall Street Journal • Feb. 9, 2026

The report concluded: "There were deviations from policy and practice, overconfidence in the ability to recruit at scale and lack of resources in vetting increased risk."

From BBC • Jan. 7, 2026

The main pluses humans have going for them are their overconfidence and yearning to manipulate anything and anyone they can for their own ends.

From Salon • Sep. 24, 2025

Grandand Rice, the preeminent sports- writer in the country, accused him of gross overconfidence.

From "Seabiscuit: An American Legend" by Laura Hillenbrand

Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023