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
Crucially, the McG cycle links with the Calvin cycle, allowing the two systems to balance out excess molecules.
—Aamir Khollam, Interesting Engineering, 13 Sep. 2025
From cracks near its south pole, the moon blasts towering geysers of water vapor, ice and organic molecules into space, which are tantalizing hints of a hidden ocean that could, in theory, be habitable.
—Sharmila Kuthunur, Space.com, 12 Sep. 2025
Then, in the late 1860s, the chemist Friedrich Miescher identified the molecule DNA, eventually leading to the unraveling of its structure by Rosalind Franklin, James Watson, and Francis Crick in 1953.
—Alan Lightman
september 12, Literary Hub, 12 Sep. 2025
In the Calvin cycle of photosynthesis, that reaction involves linking the carbon dioxide as part of a reaction that breaks apart a modified five-carbon sugar, creating two three-carbon molecules.
—ArsTechnica, 12 Sep. 2025
See All Example Sentences for molecule
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Aamir Khollam, Interesting Engineering, 13 Sep. 2025
From cracks near its south pole, the moon blasts towering geysers of water vapor, ice and organic molecules into space, which are tantalizing hints of a hidden ocean that could, in theory, be habitable.
—Sharmila Kuthunur, Space.com, 12 Sep. 2025
Then, in the late 1860s, the chemist Friedrich Miescher identified the molecule DNA, eventually leading to the unraveling of its structure by Rosalind Franklin, James Watson, and Francis Crick in 1953.
—Alan Lightman
september 12, Literary Hub, 12 Sep. 2025
In the Calvin cycle of photosynthesis, that reaction involves linking the carbon dioxide as part of a reaction that breaks apart a modified five-carbon sugar, creating two three-carbon molecules.
—ArsTechnica, 12 Sep. 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 17 Sep. 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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