mol·​e·​cule | \ ˈmä-li-ˌkyül How to pronounce molecule (audio) \

Definition of molecule

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 honestyTime

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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 Scientists sometimes call a molecule’s spectrum its fingerprint. Sarah Scoles, Wired, "‘Dr. Phosphine’ and the Possibility of Life on Venus," 14 Sep. 2020 As a team of scientists from various institutions has now reported in Nature Astronomy, one of the chemicals thus revealed appears to be PH3, or phosphine, a molecule composed of phosphorous and hydrogen. The Economist, "Planetary science Scientists find possible signs of life in the clouds of Venus," 14 Sep. 2020 The most common treatment is a molecule that gets converted to dopamine in the brain. Jonathan Wosen, San Diego Union-Tribune, "San Diego’s Neurocrine brings new Parkinson’s disease drug to market," 14 Sep. 2020 Wakely does not, however, contain even a single molecule of practical political savvy. Gilbert Garcia,, "Garcia: Green Party hopeful forced off the ballot in U.S. District 21," 21 Aug. 2020 Murchison also contained nucleobases, the building blocks of genetic molecules such as RNA, and in November 2019, researchers found a major component of RNA’s backbone: the sugar molecule ribose. Joshua Sokol, Science | AAAS, "An unusual meteorite, more valuable than gold, may hold the building blocks of life," 13 Aug. 2020 The researchers found that a molecule of dirhenium spends most of its time with a quadruple bond, sharing four electrons between the two atoms. Theresa Machemer, Smithsonian Magazine, "Watch First-Ever Footage of Atoms Forming and Breaking Bonds," 22 Jan. 2020 The team first simulated a simplified version of the energy state of a molecule consisting of 12 hydrogen atoms, with each of the 12 qubits representing one atom’s single electron. Neil Savage, Scientific American, "Google’s Quantum Computer Achieves Chemistry Milestone," 4 Sep. 2020 Probing the mechanism for these improvements, the researchers found that female mice receiving AKG produced higher levels of a molecule that tamps down on inflammation. Jocelyn Kaiser, Science | AAAS, "Bodybuilding supplement promotes healthy aging and extends life span, at least in mice," 1 Sep. 2020

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'molecule.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

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First Known Use of molecule

1701, in the meaning defined at sense 1

History and Etymology for molecule

French molécule, from New Latin molecula, diminutive of Latin moles mass

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Time Traveler for molecule

Time Traveler

The first known use of molecule was in 1701

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Statistics for molecule

Last Updated

23 Sep 2020

Cite this Entry

“Molecule.” Dictionary, Merriam-Webster, Accessed 27 Sep. 2020.

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More Definitions for molecule


How to pronounce molecule (audio)

English Language Learners Definition of molecule

: the smallest possible amount of a particular substance that has all the characteristics of that substance
: a very small amount of something


mol·​e·​cule | \ ˈmä-li-ˌkyül How to pronounce molecule (audio) \

Kids Definition of molecule

: the smallest portion of a substance having the properties of the substance a molecule of water


mol·​e·​cule | \ ˈmäl-i-ˌkyü(ə)l How to pronounce molecule (audio) \

Medical Definition of molecule

: 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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