duality
Americannoun
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a dual state or quality.
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Mathematics. a symmetry within a mathematical system such that a theorem remains valid if certain objects, relations, or operations are interchanged, as the interchange of points and lines in a plane in projective geometry.
noun
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the state or quality of being two or in two parts; dichotomy
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physics the principle that a wave-particle duality exists in microphysics in which wave theory and corpuscular theory are complementary. The propagation of electromagnetic radiation is analysed using wave theory but its interaction with matter is described in terms of photons. The condition of particles such as electrons, neutrons, and atoms is described in terms of de Broglie waves
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geometry the interchangeability of the roles of the point and the plane in statements and theorems in projective geometry
Other Word Forms
- nonduality noun
Etymology
Origin of duality
1350–1400; Middle English dualitie < Late Latin duālitās. See dual, -ity
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.
Conscious feelings are one of its techniques, emerging “deep in the subcortical regions” where the brain’s interoceptive neurons receive messages from the body and Cartesian duality dissolves.
From The Wall Street Journal • Mar. 15, 2026
"The double protagonist angle really is a feature that lets us explore the duality of the characters, but also the storyline and the different horror approaches," Nakanishi adds.
From BBC • Feb. 27, 2026
California’s 41st governor, a possible suitor for the White House, opens up about the duality of his upbringing in his new book.
From Los Angeles Times • Feb. 15, 2026
The new duality, Li says, involves materials that can behave as both conductors and insulators.
From Science Daily • Nov. 9, 2025
A nice way of visualizing the wave/particle duality is the so-called sum over histories introduced by the American scientist Richard Feynman.
From "A Brief History of Time: And Other Essays" by Stephen Hawking
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.
