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

Keep scrolling for more

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 Further research showed that the molecule is able to deactivate viruses by chopping off parts of their DNA. Rasha Aridi, Smithsonian Magazine, "Two Scientists Receive the Nobel Prize in Chemistry for Their Discovery of CRISPR," 7 Oct. 2020 One is a single molecule of RNA that homes in on the genetic target. Brianna Abbott, WSJ, "Nobel Prize in Chemistry Is Awarded for Crispr Gene-Editing Technology," 7 Oct. 2020 Gilead invented the molecule that would become remdesivir during a search for treatments for hepatitis C a decade ago. Washington Post, "Remdesivir may not cure coronavirus, but it’s on track to make billions for Gilead," 30 Sep. 2020 But at high concentrations, the molecule can be harmful to humans. Larissa Zimberoff,, "Startups Race to Develop Tech That Can Clear Workplaces of Covid," 18 Sep. 2020 Based on the team’s calculations, none of those events could produce the molecule in such abundance. Nadia Drake, National Geographic, "Possible sign of life on Venus stirs up heated debate," 14 Sep. 2020 Scientists have discovered the molecule elsewhere in the solar system, in the cores of the planets Jupiter and Saturn. Jennifer Leman, Popular Mechanics, "We've Found Possible Signs of Life in Venus's Clouds. Whoa.," 14 Sep. 2020 Scott Dax, a medicinal chemist and the company’s chief scientific officer, discovered the molecule that the company believes could change the way doctors treat pain. Dom Difurio, Dallas News, "UT Dallas biotech startup pursuing non-opioid pain therapy sells to California firm for $52.5 million," 25 Aug. 2020 The shape of the remdesivir molecule resembles one of these bases. Joseph Walker, WSJ, "All Remdesivir Supplies to Be Distributed in U.S. by Maker Gilead Sciences," 1 Oct. 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.

See More

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

Keep scrolling for more

Learn More about molecule

Time Traveler for molecule

Time Traveler

The first known use of molecule was in 1701

See more words from the same year

Statistics for molecule

Last Updated

17 Oct 2020

Cite this Entry

“Molecule.” Dictionary, Merriam-Webster, Accessed 26 Oct. 2020.

Keep scrolling for more

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

Keep scrolling for more

Comments on molecule

What made you want to look up molecule? Please tell us where you read or heard it (including the quote, if possible).


Test Your Vocabulary

Namesakes Word Quiz

  • a citrus fruit possibly named after a person
  • Which of the following is a fruit named after a Moroccan seaport?
Spell It

Can you spell these 10 commonly misspelled words?


Test Your Knowledge - and learn some interesting things along the way.

Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!