molecule
noun
mol·e·cule
ˈmä-li-ˌkyül 
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.
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
Blue and purple auroras are typically linked to nitrogen molecules.
—
Samantha Mathewson, Space.com, 26 May 2026
Metabolomics is a larger-scale study of small molecules serving as end products of cellular processes, according to UC San Diego.
—Noah Lyons, San Diego Union-Tribune, 26 May 2026
They’re released into the shallow mantle and can soon come back into the atmosphere via volcanoes, ready to scavenge any plucky molecules of oxygen present in the atmosphere.
—Scott K. Johnson, ArsTechnica, 26 May 2026
In 2019, the FDA released a study showing that certain molecules in chemical sunscreens—such as avobenzone, ecamsule, octocrylene and oxybenzone—may be absorbed into the bloodstream, calling for further investigation.
—Jackie Flynn Mogensen, Scientific American, 25 May 2026
See All Example Sentences for molecule
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Samantha Mathewson, Space.com, 26 May 2026
Metabolomics is a larger-scale study of small molecules serving as end products of cellular processes, according to UC San Diego.
—Noah Lyons, San Diego Union-Tribune, 26 May 2026
They’re released into the shallow mantle and can soon come back into the atmosphere via volcanoes, ready to scavenge any plucky molecules of oxygen present in the atmosphere.
—Scott K. Johnson, ArsTechnica, 26 May 2026
In 2019, the FDA released a study showing that certain molecules in chemical sunscreens—such as avobenzone, ecamsule, octocrylene and oxybenzone—may be absorbed into the bloodstream, calling for further investigation.
—Jackie Flynn Mogensen, Scientific American, 25 May 2026
See All Example Sentences for molecule
Cite this Entry
“Molecule.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/molecule. Accessed 27 May. 2026.
Copy CitationKids Definition
molecule
noun
mol·e·cule
ˈmäl-i-ˌkyü(ə)l
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
: 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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