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

Synonyms

• atom
• bit
• crumb
• dribble
• fleck
• flyspeck
• grain
• granule
• morsel
• mote
• nubbin
• nugget
• particle
• patch
• scrap
• scruple
• snip
• snippet
• speck
• tittle

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

Allure has reported on the rising interest in exosomes—nanoparticles released by cells in the human body that carry various molecules and may send signals to skin cells to repair and regenerate—since 2022. —Victoria Moorhouse, Allure, 12 Dec. 2024

These molecules stimulate hair and skin growth, regulate metabolism, boost bone health, and in some cases may even be anti-inflammatory. —Sandee Lamotte, CNN, 11 Dec. 2024

This can be done through a variety of methods including separating the uranium isotopes with a laser, or through gaseous diffusion, in which uranium hexafluoride is fed through pipes with filters to separate the molecules in the uranium isotopes. —Paul Du Quenoy, Newsweek, 9 Dec. 2024

The disease alters the structure of hemoglobin, the molecule in red blood cells that delivers oxygen to organs and tissue throughout the body. —Joshua P. Cohen, Forbes, 7 Dec. 2024

Word History

Etymology

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

First Known Use

1701, in the meaning defined at sense 1

Kids 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