Cleavage can refer to different things depending on the context. Here are some definitions:

• Embryology: In embryology, cleavage is the division of cells in the early development of the embryo, following fertilization. The zygotes of many species undergo rapid cell cycles with no significant overall growth, producing a cluster of cells the same size. Cleavage differs from other forms of cell division in that it increases the number of cells and nuclear mass without increasing the cytoplasmic mass. This means that with each successive subdivision, there is roughly half the cytoplasm in each daughter cell than before that division, and thus the ratio of nuclear to cytoplasmic material increases).

• Geology: In geology, cleavage refers to the way in which a crystal or mineral tends to split.

• Chemistry and biochemistry: In chemistry and biochemistry, cleavage refers to the splitting of chemical bonds.

• Anatomy: In anatomy, cleavage can refer to the partial exposure of certain body parts, such as the gap between a womans breasts (breast cleavage), the minor exposure of the buttocks and the gluteal cleft between them (buttock cleavage), or the partial exposure of toes in shoes (toe cleavage) .

• Other uses: Cleavage can also refer to the divisions of society that cause people to vote differently (political cleavage) .

It is important to note that the term "cleavage" can have different meanings depending on the context.