chi·​ral ˈkī-rəl How to pronounce chiral (audio)
: of or relating to a molecule that is not superimposable on its mirror image
chirality noun

Example Sentences

Recent Examples on the Web Spearmint and caraway oils are mutually chiral. Rebecca Coffey, Forbes, 9 Dec. 2021 The amino acids and sugars that make up our bodies are chiral. Nathaniel Scharping, Discover Magazine, 14 Dec. 2016 However, the dirt reacting with chiral selectivity would change the picture dramatically. David Warmflash, Discover Magazine, 20 July 2016 Think of chiral molecules as being like a pair of gloves. Nathaniel Scharping, Discover Magazine, 14 Dec. 2016 For example, chiral molecular materials—molecules that exist as a pair of non-superimposable mirror images—will revolutionize quantum technologies. Jessica Wade, WIRED, 27 Dec. 2022 The classic example is chiral perturbation theory, which replaces the quarks and gluons of quantum chromodynamics with the pions and nucleons of the low-energy world. Sean Carroll, Discover Magazine, 19 Apr. 2011 And every molecule involved churns out chiral products. Byrobert F. Service,, 27 Oct. 2022 At a cutoff of 1 GeV, for example, chiral effective field theory stops working, because protons and neutrons stop behaving like single particles and instead act like trios of quarks. Quanta Magazine, 1 Mar. 2022 See More

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

Word History


chir- + -al entry 1

First Known Use

1894, in the meaning defined above

Time Traveler
The first known use of chiral was in 1894

Dictionary Entries Near chiral

Cite this Entry

“Chiral.” Dictionary, Merriam-Webster, Accessed 2 Jun. 2023.

Medical Definition


chi·​ral ˈkī-rəl How to pronounce chiral (audio)
of a molecule : having a structure that is nonsuperimposable on its mirror image
chiral molecules
: relating to or composed of chiral molecules
In discussions of chiral drugs, thalidomide is sometimes cited as a prime example of a drug that differs strikingly in the properties of its two enantiomers.Stephen C. Stinson, Chemical & Engineering News
: of, relating to, or being a chiral center
chirality noun
plural chiralities
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