duality

[ doo-al-i-tee, dyoo- ]

noun

1. a dual state or quality.
2. 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.

duality

/ djuːˈælɪtɪ /

noun

1. the state or quality of being two or in two parts; dichotomy
2. 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
3. geometry the interchangeability of the roles of the point and the plane in statements and theorems in projective geometry

Other Words From

• nondu·ali·ty noun

Word History and Origins

Origin of duality¹

1350–1400; Middle English dualitie < Late Latin duālitās. See dual, -ity

Example Sentences

On one level, that duality reflects the abiding tensions within many Muslim nations.

From Time

She remains that fascinating duality, a skillset more common than when she first entered the league because she was so transcendent that a generation since has consciously tried to emulate her.

From FiveThirtyEight

Wave-particle duality turned out to be a symptom of a deep strangeness.

From Quanta Magazine

The duality of the Frye twins introduced respective, unique skill trees to unlock.

From Washington Post

The new calculations say much the same thing, but without committing to the duality or to string theory.

From Quanta Magazine

Buried halfway underground, the work has a duality of life and death—is it growing or is it a tomb?

From The Daily Beast

“We liked the duality of these low-plunging costumes because Amy could slip from being confident to vulnerable,” says Wilkinson.

From The Daily Beast

Much like the duality of his shop, Simon is half goateed-rocker, half cicerone sage.

From The Daily Beast

That duality is represented by Tom Ford more than any other designer.

From The Daily Beast

As a ballerina, to embody the duality of the Swan Queen and the black swan can be a fiendishly difficult task.

From The Daily Beast

He saw her struggles and her tears… the mysterious duality working to possess her soul.

From Project Gutenberg

They were a duality the constitutive forces of which alternately assumed supremacy.

From Project Gutenberg

Duality is the root, out of which alone, for mortals, happiness can spring.

From Project Gutenberg

From the top to the bottom of the sexual scale the new being springs invariably from a duality.

From Project Gutenberg

I shall merely pause here in my narrative to indicate this duality, this perplexing mixing of personality.

From Project Gutenberg

Related Words

• combination
• couple
• duo
• match
• team
• two