molecule

noun

mol·​e·​cule ˈmä-li-ˌkyül How to pronounce molecule (audio)
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
a molecule of political honestyTime

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.
Air molecules in Earth's atmosphere scatter most of the blue light, causing the remaining light to reflect onto the moon with a red glow, according to NASA. Melina Khan, USA Today, 6 Sep. 2025 Gold nanoclusters, which contain fewer than 100 atoms, are usually created by giving gold ions extra electrons while surrounding molecules called ligands keep them stable. Rupendra Brahambhatt, Interesting Engineering, 6 Sep. 2025 Air molecules in Earth's atmosphere scatter most of the blue light, causing the remaining light to reflect onto the moon with a red glow, according to NASA. Marina Johnson, Louisville Courier Journal, 5 Sep. 2025 In experiments, by analyzing the spectral features of these vibropolaritons, the new quantum sensor was able to identify an organic molecule known as 4-mercaptobenzonitrile dissolved in an organic solvent. IEEE Spectrum, 4 Sep. 2025 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

Browse Nearby Words

Cite this Entry

“Molecule.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/molecule. Accessed 9 Sep. 2025.

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

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