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
As long as that coumarin molecule is bound to the drug, which is known as Penicillin-PPG (Photocleavable Protecting Groups), the antibiotic remains inactive.
—Ben Coxworth, New Atlas, 13 June 2025
At the heart of more than 50 different neurodegenerative diseases is the molecule amyloid beta.
—Ian Randall, MSNBC Newsweek, 13 June 2025
Creatine is a molecule that helps the body recycle adenosine triphosphate (ATP), the key source of energy for cells throughout the body.
—Staff Author Published, Verywell Health, 11 June 2025
Some medications are based on molecules that are mirror images of natural molecules.
—Eva Amsen, JSTOR Daily, 11 June 2025
See All Example Sentences for molecule
Examples are automatically compiled from online sources to
show current usage.
Read More
Opinions expressed in the examples do not represent those of Merriam-Webster or its editors.
Send us feedback.
Ben Coxworth, New Atlas, 13 June 2025
At the heart of more than 50 different neurodegenerative diseases is the molecule amyloid beta.
—Ian Randall, MSNBC Newsweek, 13 June 2025
Creatine is a molecule that helps the body recycle adenosine triphosphate (ATP), the key source of energy for cells throughout the body.
—Staff Author Published, Verywell Health, 11 June 2025
Some medications are based on molecules that are mirror images of natural molecules.
—Eva Amsen, JSTOR Daily, 11 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 30 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
Love words? Need even more definitions?
Merriam-Webster unabridged
Share