1. (尤指女子穿低胸服时露出的)乳沟
A woman's cleavage is the space between her breasts, especially the top part which you see if she is wearing a dress with a low neck.

2. 裂痕;裂隙;分歧
A cleavage between two people or things is a division or disagreement between them.

1. the act of cleaving or splitting

2. the line formed by a groove between two parts (especially the separation between a woman's breasts)

3. (embryology) the repeated division of a fertilised ovum

Synonym: segmentation

4. the breaking of a chemical bond in a molecule resulting in smaller molecules

5. the state of being split or cleft

e.g. there was a cleavage between the liberal and conservative members