cleavage

noun

cleav·​age ˈklē-vij 

1

a

: the quality of a crystallized substance or rock of splitting along definite planes

also : the occurrence of such splitting

b

: a fragment (as of a diamond) obtained by splitting

2

: the action of cleaving or splitting : the state of being cleft

3

: the series of synchronized mitotic cell divisions of a fertilized egg that results in the formation of the blastomeres and changes the single-celled zygote into a multicellular embryo

also : one of these cell divisions

4

: the splitting of a molecule into simpler molecules

5

: the depression between a woman's breasts especially when made visible by a low-cut neckline

Synonyms of cleavage

• split
• dissolution
• breakup
• partition
• division
• separation

Examples of cleavage in a Sentence

The dress is cut low enough to reveal a lot of cleavage.

the cleavage between the rich and poor

the cleavages of an egg as an embryo develops

Recent Examples on the Web

The cartoonist and journalist Joe Sacco has made a career of rescuing history from the cleavages of memory. —Robert Rubsam, The Atlantic, 18 Dec. 2025

Intelligence agencies in the United States and other Western countries closely follow these cleavages, of course, and can sometimes recruit the disaffected or the ambitious to provide insider information. —Stephen Kotkin, Foreign Affairs, 16 Dec. 2025

The design featured bold shoulders, a slit down the center that showed off a bit of cleavage, as well as a slit near the knee. —Michelle Lee, PEOPLE, 24 Nov. 2025

Mickey Guyton Mickey Guyton rocked a black two-piece set, featuring a cropped collared shirt left unbuttoned to reveal a hint of cleavage, and a mermaid skirt, with both the skirt and the top featuring sparkling fringe. —Lori A Bashian, FOXNews.com, 20 Nov. 2025

Word History

First Known Use

1816, in the meaning defined at sense 1a

Phrases Containing cleavage

• discoidal cleavage
• radial cleavage
• spiral cleavage

Kids Definition

cleavage

noun

cleav·​age ˈklē-vij 

1

: the quality of a crystallized substance or rock of splitting in definite directions

2

: the action of cleaving : the state of being cleaved

3

: the series of mitotic cell divisions of a fertilized egg that changes the single cell into a many-celled embryo

Medical Definition

cleavage

noun

cleav·​age ˈklē-vij 

1

: the series of synchronized mitotic cell divisions of the fertilized egg that results in the formation of the blastomeres and changes the single-celled zygote into a multicellular embryo

also : one of these cell divisions

2

: the splitting of a molecule into simpler molecules