twin·​ning ˈtwi-niŋ How to pronounce twinning (audio)
: the act of producing or giving birth to twins
Rates of fraternal twinning vary from population to population, and the tendency to produce fraternal twins is genetically transmitted through the mother's line.Jane E. Brody
The frequency of twinning among women who have already borne twins, the 'repeat frequency,' is significantly higher than in the general population.P. Parisi et al.
: the coupling, association, or comparison of two similar people, groups, or things
It also encourages twinning between rich and poor parishes.Thomas J. Reese
The rhapsodizing literature and the inherent twinning of Disney's theme parks and its new town drew people with unrealistic dreams.Douglas Frantz et al.
: the assemblage of two or more crystals or parts of crystals such that they form a twin (see twin entry 1 sense 3)
One of them, a spiral defect, typically occurs when atoms crystallize from a high-temperature vapor. In the other defect, known as twinning, atomic lattices that are mirror images of each other join at a common boundary.R. Cowen
The two-time Nobel laureate Linus Pauling, for example, championed an arrangement of ordinary crystals called twinning. Twinned crystals grow from separate origins and penetrate each other at odd angles, such as 72 degrees. This might produce a diffraction pattern with spurious fivefold symmetry, even though the underlying structure was conventional.Hans C. Von Baeyer

Examples of twinning in a Sentence

Recent Examples on the Web But since monozygotic twinning seems to happen randomly, mothers of identical twins would presumably dilute the effect seen here. Elizabeth Preston, Discover Magazine, 15 Aug. 2011 According to the Poosh founder, the spooky twinning was entirely an accident — neither sister told the other about their costume plans. Bailey Richards, Peoplemag, 1 Oct. 2023 Immediately after the latter arrived, the internet was quick to notice and meme about the two twinning. Zizi Strater, Peoplemag, 3 May 2023 And more than 42% of executives across a broad spectrum of industry verticals understand the benefits of digital twinning, with 59% planning to incorporate the technology within their operations by 2028. Jennifer Kite-Powell, Forbes, 16 May 2022 Regal twinning at coronation catches eyes Princess Catherine of Wales and her daughter, Princess Charlotte, made a statement in matching silver headpieces. Alexandra Meeks, CNN, 8 May 2023 The pair also stepped out for Halloween weekend with a creepy twinning look to cap off festivities, going as the ghostly twins from Stanley Kubrick's 1980 horror film The Shining. Brenton Blanchet, Peoplemag, 5 Nov. 2022 Scroll to see Warwick and Taylor twinning. Brooklyn White, Essence, 23 Dec. 2020 That twinning adds to the play’s air of sad mystery. Vinson Cunningham, The New Yorker, 3 Oct. 2022 See More

These examples are programmatically compiled from various online sources to illustrate current usage of the word 'twinning.' Any opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback about these examples.

Word History

First Known Use

1573, in the meaning defined at sense 1

Time Traveler
The first known use of twinning was in 1573

Dictionary Entries Near twinning

Cite this Entry

“Twinning.” Dictionary, Merriam-Webster, Accessed 5 Dec. 2023.

Medical Definition


twin·​ning ˈtwin-iŋ How to pronounce twinning (audio)
: the bearing of twins

More from Merriam-Webster on twinning

Last Updated: - Updated example sentences
Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!