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

There is a molecule of evidence to support these charges.

Synonyms of molecule

• particle
• speck
• atom
• bit
• patch
• fleck
• grain
• snippet
• scrap
• granule
• mouthful
• crumb
• shred

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

That behavior resembles a liquid crystal, where molecules can move freely but still maintain directional alignment. — Aamir Khollam, Interesting Engineering, 3 Oct. 2026

According to Microban, the treatment captures and neutralizes odor molecules, with performance lasting up to 50 home launderings. — Alexandra Harrell, Footwear News, 2 Oct. 2026

Novo is also developing another treatment called amycretin, or zenagamtide, which is a single molecule that would target both GLP-1 and amylin to treat obesity and Type 2 diabetes. — Annika Kim Constantino, CNBC, 2 Oct. 2026

The kettle ostensibly includes a spout through which people are released as molecules are split from their collective bonds. — Sophie Landres, Artforum, 1 Oct. 2026

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

Rhymes for molecule

• minuscule
• overrule
• poiseuille
• reticule
• ridicule
• vestibule
• ampoule
• bascule
• carpool
• cesspool
• ferrule
• footstool

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