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 oxygen and nitrogen molecules also emit ultraviolet light, which can only be detected by special cameras on satellites.
—
Jenna Prestininzi, Freep.com, 7 Nov. 2025
Others, however, were betting on DNA, a mysterious molecule that was first identified in the 1860s and found in basically every type of cell that scientists studied.
—Nell Greenfieldboyce, NPR, 7 Nov. 2025
Frozen complex organic molecules have been discovered for the first time around a young protostar in a galaxy other than our own, thanks to the observing power of the James Webb Space Telescope (JWST).
—Keith Cooper, Space.com, 7 Nov. 2025
The motion of the bead against the rod causes the atoms/molecules/electrons to rub against one another, producing heat through friction, and thereby providing a method for extracting energy from the gravitational waves.
—Big Think, 7 Nov. 2025
See All Example Sentences for molecule
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Jenna Prestininzi, Freep.com, 7 Nov. 2025
Others, however, were betting on DNA, a mysterious molecule that was first identified in the 1860s and found in basically every type of cell that scientists studied.
—Nell Greenfieldboyce, NPR, 7 Nov. 2025
Frozen complex organic molecules have been discovered for the first time around a young protostar in a galaxy other than our own, thanks to the observing power of the James Webb Space Telescope (JWST).
—Keith Cooper, Space.com, 7 Nov. 2025
The motion of the bead against the rod causes the atoms/molecules/electrons to rub against one another, producing heat through friction, and thereby providing a method for extracting energy from the gravitational waves.
—Big Think, 7 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 10 Nov. 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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