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
a molecule of political honesty—
Time
TimeExamples 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
Methylene blue inhibits a molecule called monoamine oxidase, whose job is to break down an important brain chemical, serotonin.
—Lorne J. Hofseth, The Conversation, 3 June 2025
Gao and his colleagues wanted to find a molecule that could replenish a dead cell by infusing it with lithium ions.
—You Xiaoying, Scientific American, 2 June 2025
Digestion: Complex carbohydrates take longer to digest because the body must break them down into individual sugar molecules for use.
—Melissa Nieves, Verywell Health, 2 June 2025
Working meticulously over sometimes long periods of time, looking at human cells and the molecules within them, Souers said the scientists look for ways to kill the malignant cells to improve a patient’s condition.
—Steve Sadin, Chicago Tribune, 2 June 2025
See All Example Sentences for molecule
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Lorne J. Hofseth, The Conversation, 3 June 2025
Gao and his colleagues wanted to find a molecule that could replenish a dead cell by infusing it with lithium ions.
—You Xiaoying, Scientific American, 2 June 2025
Digestion: Complex carbohydrates take longer to digest because the body must break them down into individual sugar molecules for use.
—Melissa Nieves, Verywell Health, 2 June 2025
Working meticulously over sometimes long periods of time, looking at human cells and the molecules within them, Souers said the scientists look for ways to kill the malignant cells to improve a patient’s condition.
—Steve Sadin, Chicago Tribune, 2 June 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 9 Jun. 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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