Cleavage
Part of speech: noun
Definition: The act of cleaving or the state of being cleft. The tendency of a crystal to split along specific planes. The repeated division of a cell into daughter cells after mitosis. The hollow or separation between a woman's breasts, especially as revealed by a low neckline. The splitting of a large molecule into smaller ones.
Example sentence: I like the collarbone, a very clean collarbone. I think there's something also very delicate and balletic about that part of a woman's body, and I'm not really a cleavage person, but I do like a back or a shoulder; I think there's something very alluring about backless dresses.
Segmentation
Part of speech: noun
Definition: The process of dividing into segments.