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

The findings could help astronomers better understand how material is recycled in the centers of galaxies and the role evolved stars play in supplying those regions with fresh dust and molecules. — Samantha Mathewson, Space.com, 14 Aug. 2026

Initially introduced in 2018, these are thin layers of molecules that act like molecular glue. — Georgina Jedikovska, Interesting Engineering, 14 Aug. 2026

This means that molecules’ radio signals can be compared to calculate those quantities. — Olivia Harper Wilkins, The Conversation, 14 Aug. 2026

The new version’s makeup consists of six plant extracts and five active molecules, as well as turmeric to reduce aging, dark circles, and puffiness. — Tessa Petak, InStyle, 14 Aug. 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