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
What’s more, this innovation has been achieved without the use of new chemicals but through the use of polymer molecules folded in space.
—
Christopher McFadden, Interesting Engineering, 29 Nov. 2025
Purple carrots, for example, have been shown to have the highest antioxidant activity due to their high concentration of phenolic compounds,3 which are naturally occurring plant molecules with antioxidant and anti-inflammatory properties.
—Emily Brown, Verywell Health, 28 Nov. 2025
AlphaFold 3, for instance, predicts not just protein structures but several critical aspects of how proteins bind with one another and with small molecules.
—Jeremy Kahn, Fortune, 28 Nov. 2025
Be thankful for the atoms and molecules that have assembled to make you.
—Big Think, 27 Nov. 2025
See All Example Sentences for molecule
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Christopher McFadden, Interesting Engineering, 29 Nov. 2025
Purple carrots, for example, have been shown to have the highest antioxidant activity due to their high concentration of phenolic compounds,3 which are naturally occurring plant molecules with antioxidant and anti-inflammatory properties.
—Emily Brown, Verywell Health, 28 Nov. 2025
AlphaFold 3, for instance, predicts not just protein structures but several critical aspects of how proteins bind with one another and with small molecules.
—Jeremy Kahn, Fortune, 28 Nov. 2025
Be thankful for the atoms and molecules that have assembled to make you.
—Big Think, 27 Nov. 2025
See All Example Sentences for molecule
Cite this Entry
“Molecule.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/molecule. Accessed 1 Dec. 2025.
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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