enantiomer

noun

en·​an·​tio·​mer i-ˈnan-tē-ə-mər How to pronounce enantiomer (audio)
: either of a pair of chemical compounds whose molecular structures have a nonsuperimposable mirror-image relationship to each other compare diastereomer
enantiomeric adjective

Examples of enantiomer in a Sentence

Recent Examples on the Web
Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.
If the wrong enantiomers slip into pharmaceuticals, the effects can sometimes be toxic or even lethal. Yasemin Saplakoglu, Quanta Magazine, 6 Sep. 2023 Once a crystal seed forms from the enantiomer that is attracted to the surface, the crystal preferentially grows by incorporating more of the same enantiomer. Yasemin Saplakoglu, Quanta Magazine, 6 Sep. 2023 And then there’s the case of esketamine, which is the S-enantiomer of ketamine, a similar (in molecular structure) but more potent agent than ketamine. Joshua Cohen, Forbes, 5 July 2021 Ketamine is a combination of two enantiomers, or mirror image molecules. Megan Thielking, Scientific American, 6 Mar. 2019 Strangely enough, meth's enantiomer is the active ingredient in Vick's Vapor Inhaler. William Herkewitz, Popular Mechanics, 19 Aug. 2013

Word History

Etymology

Greek enantios + English -mer

First Known Use

circa 1929, in the meaning defined above

Time Traveler
The first known use of enantiomer was circa 1929

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Cite this Entry

“Enantiomer.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/enantiomer. Accessed 28 Feb. 2025.

Medical Definition

enantiomer

noun
en·​an·​tio·​mer in-ˈant-ē-ə-mər How to pronounce enantiomer (audio)
: either of a pair of chemical compounds whose molecular structures have a mirror-image relationship to each other

called also optical antipode

enantiomeric adjective
enantiomerically adverb

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