molecule

noun

mol·​e·​cule ˈmä-li-ˌkyül How to pronounce molecule (audio)
Synonyms of moleculenext
1
: the smallest particle of a substance that retains all the properties (see property sense 1a) of the substance and is composed of one or more atoms (see atom sense 1a)
a molecule of water
a molecule of oxygen
2
: a tiny bit : particle
There is a molecule of evidence to support these charges.

Synonyms of molecule

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Examples of molecule in a Sentence

There is not a molecule of evidence to support these charges. not a molecule of sense in that girl
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.
These clouds tend to cool down, because fast-moving molecules will collide with other molecules and lose energy. — Perri Thaler, Quanta Magazine, 30 Oct. 2026 Its molecules are too large to penetrate the skin and stimulate new production, Scott explains; applied topically, the protein acts more like a humectant (water-attracting substance), helping to retain moisture. — Amy Francombe, Vogue, 30 Oct. 2026 These compounds help prevent an overabundance of free radicals (unstable molecules) that can damage DNA and lead to oxidative stress and inflammation. — Angelica Bottaro, Verywell Health, 29 Oct. 2026 Unlike treatments that mask odors with fragrance, Livinguard Fresh targets odor molecules directly on the textile surface. — Alexandra Harrell, Footwear News, 29 Oct. 2026 See All Example Sentences for molecule

Word History

Etymology

French molécule, from New Latin molecula, diminutive of Latin moles mass

First Known Use

1701, in the meaning defined at sense 1

Time Traveler
The first known use of molecule was in 1701

Rhymes for molecule

See All Rhymes for molecule

Browse Nearby Words

molecular weight
molecule
moled
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Cite this Entry

“Molecule.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/molecule. Accessed 1 Nov. 2026.

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Kids Definition

molecule

noun
mol·​e·​cule ˈmäl-i-ˌkyü(ə)l How to pronounce molecule (audio)
1
: the smallest particle of a substance having all the characteristics of the substance
a molecule of water
a molecule of oxygen
2
: a very small bit : particle

Medical Definition

molecule

noun
mol·​e·​cule ˈmäl-i-ˌkyü(ə)l How to pronounce molecule (audio)
: the smallest particle of a substance that retains all the properties of the substance and is composed of one or more atoms

More from Merriam-Webster on molecule

Britannica.com: Encyclopedia article about molecule

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