cleavage

The story

From cleave + -age.

First known use, by meaning

• from 19th c. The act of cleaving or the state of being cleft.
• from 20th c. The hollow or separation between a woman's breasts, especially as revealed by a low neckline.
• from 19th c. The repeated division of a cell into daughter cells after mitosis.
• from 19th c. The tendency of a crystal to split along specific planes; schistosity.