Nouns

(n)cleavagethe state of being split or cleft“there was a cleavage between the liberal and conservative members”
(n)cleavagethe breaking of a chemical bond in a molecule resulting in smaller molecules
(n)cleavage, segmentation(embryology) the repeated division of a fertilised ovum
(n)cleavagethe line formed by a groove between two parts (especially the separation between a woman's breasts)
(n)cleavagethe act of cleaving or splitting