counterexample

American

[koun-ter-ig-zam-puhl, -zahm-] / ˈkaʊn tər ɪgˌzæm pəl, -ˌzɑm- /

noun

an example that refutes an assertion or claim.

counterexample British

/ ˈkaʊntərɪɡˌzɑːmpəl /

noun

an example or fact that is inconsistent with a hypothesis and may be used in argument against it

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Etymology

Origin of counterexample

First recorded in 1955–60; counter- + example

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.

South Africa’s nuclear dismantlement during its transition from apartheid to democracy in the early 1990s offers a positive counterexample.

From The Wall Street Journal • Feb. 1, 2026

Argentina offers a solid counterexample: Voters reward discipline.

From Barron's • Nov. 4, 2025

Chamberlain, Vanderbilt University geologist Steven Goodbred, and colleagues stumbled on a counterexample by chance.

From Science Magazine • Jun. 17, 2024

An excellent pairing with the 2022 Sundance premiere “We Met in Virtual Reality,” “Ibelin” is a poignant counterexample to the technodoomerism that often accompanies relationships formed in virtual spaces.

From New York Times • Jan. 28, 2024

Show, by means of a counterexample, that the converse is false.

From "The Curious Incident of the Dog in the Night-Time" by Mark Haddon

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