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
Water molecules migrate toward the saltier side, but the membrane blocks salt ions from passing.
—Tejasri Gururaj, Interesting Engineering, 24 Oct. 2025
Today, scientists are extremely excited about how AI can be used to predict the way molecules interact, transforming areas like drug discovery and materials science.
—Reed Albergotti, semafor.com, 22 Oct. 2025
Additional experiments showed that certain signals from the cells’ environment — including one molecule called KIT ligand, which promotes cell growth — helped determine which way the cells went, the release stated.
—Khloe Quill, FOXNews.com, 22 Oct. 2025
For each sculpture, Tolaas captured molecules present during its material creation, alongside scents drawn from the animals themselves, their habitats and their interactions with humans.
—Sofia Celeste, Footwear News, 22 Oct. 2025
See All Example Sentences for molecule
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Tejasri Gururaj, Interesting Engineering, 24 Oct. 2025
Today, scientists are extremely excited about how AI can be used to predict the way molecules interact, transforming areas like drug discovery and materials science.
—Reed Albergotti, semafor.com, 22 Oct. 2025
Additional experiments showed that certain signals from the cells’ environment — including one molecule called KIT ligand, which promotes cell growth — helped determine which way the cells went, the release stated.
—Khloe Quill, FOXNews.com, 22 Oct. 2025
For each sculpture, Tolaas captured molecules present during its material creation, alongside scents drawn from the animals themselves, their habitats and their interactions with humans.
—Sofia Celeste, Footwear News, 22 Oct. 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 30 Oct. 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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