cleavage

American  

[klee-vij] / ˈkli vɪdʒ /

noun

1. the act of cleaving cleave or splitting.

2. the state of being cleft. cleave. cleft.

3. the area between a woman's breasts, especially when revealed by a low-cut neckline.

4. a critical division in opinion, beliefs, interests, etc., as leading to opposition between two groups.

   a growing cleavage between the Conservative and Liberal wings of the party.

5. the tendency of crystals, certain minerals, rocks, etc., to break in preferred directions so as to yield more or less smooth surfaces cleavageplanes.

6. Embryology. the total or partial division of the egg into smaller cells or blastomeres.

7. Also called scission.  Chemistry. the breaking down of a molecule or compound into simpler structures.

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cleavage British  

/ ˈkliːvɪdʒ /

noun

1. informal the separation between a woman's breasts, esp as revealed by a low-cut dress

2. a division or split

3. (of crystals) the act of splitting or the tendency to split along definite planes so as to yield smooth surfaces

4. Also called: segmentation.  embryol (in animals) the repeated division of a fertilized ovum into a solid ball of cells (a morula), which later becomes hollow (a blastula)

5. the breaking of a chemical bond in a molecule to give smaller molecules or radicals

6. geology the natural splitting of certain rocks, or minerals such as slates, or micas along the planes of weakness

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cleavage Scientific  

/ klē′vĭj /

1. Geology The breaking of certain minerals along specific planes, making smooth surfaces. These surfaces are parallel to the faces of the molecular crystals that make up the minerals. A mineral that exhibits cleavage breaks into smooth pieces with the same pattern of parallel surfaces regardless of how many times it is broken. Some minerals, like quartz, do not have a cleavage and break into uneven pieces with rough surfaces.

2. Biology

   1. The series of mitotic cell divisions by which a single fertilized egg cell becomes a many-celled blastula. Each division produces cells half the size of the parent cell.

   2. Any of the single cell divisions in such a series.

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cleavage Cultural  

1. The process by which an animal cell divides into two daughter cells after mitosis. In an embryo, this process is repeated many times and leads to the formation of the blastula.

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Etymology

Origin of cleavage

First recorded in 1810–20; cleave ² + -age

Explanation

Cleavage is a word for a kind of splitting or separation: it's mainly used for the split between a woman's breasts. We can talk about many kinds of cleavage, such as the splitting of a cell or a hunk of wood. Political movements will often have a cleavage, as differences of opinion create factions. This word is interesting because cleavage is not only a separation, but it can mean a bringing together. When you think of the cleavage created by a woman's breasts — stop staring, by the way — you can see the separation and bringing together very well.

Example Sentences

“It created a cleavage with the United States that was really necessary.”

From The Wall Street Journal • Mar. 1, 2026

“Although race is often cited as the central cleavage in America, the single most powerful predictor of voting intention is religion,” the Economist noted.

From Seattle Times • Apr. 13, 2024

Locked, backtracked complexes are less likely to be rescued by TFIIS-driven cleavage, and more likely to delay transcription of the gene involved.

From Science Daily • Feb. 9, 2024

Going after its leaders would risk a major cleavage.

From Slate • Dec. 18, 2023

She had memorized a phrase: cleavage; epiboly, and organogenesis.

From "Son" by Lois Lowry

Related Words

• chasm
• rift
• schism