Meaning of CLEAVAGE in English

■ noun

1》 a marked difference or division between people.

2》 the cleft between a woman's breasts.

3》 Biology cell division, especially of a fertilized egg cell.

4》 the splitting of rocks or crystals in a preferred plane or direction.

Concise Oxford English vocab.      Сжатый оксфордский словарь английского языка.