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
The light triggered a chemical rearrangement inside the crystal, reshaping its internal architecture and creating tiny cavities capable of trapping water molecules from the air.
—
Neetika Walter, Interesting Engineering, 12 May 2026
Jet fuel and diesel are both classified as middle distillates and rely on the same portion of crude molecules.
—CNBC, 12 May 2026
Under oxidative stress, harmful molecules called reactive oxygen species (ROS) directly damage cellular DNA, causing cells to age prematurely.
—Md Published, Verywell Health, 11 May 2026
Since then, scientists have devised ways of redesigning these molecules to better infiltrate muscle cells, leading to vastly higher dystrophin levels.
—Jason Mast, STAT, 7 May 2026
See All Example Sentences for molecule
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Neetika Walter, Interesting Engineering, 12 May 2026
Jet fuel and diesel are both classified as middle distillates and rely on the same portion of crude molecules.
—CNBC, 12 May 2026
Under oxidative stress, harmful molecules called reactive oxygen species (ROS) directly damage cellular DNA, causing cells to age prematurely.
—Md Published, Verywell Health, 11 May 2026
Since then, scientists have devised ways of redesigning these molecules to better infiltrate muscle cells, leading to vastly higher dystrophin levels.
—Jason Mast, STAT, 7 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 19 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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