cleavage
/ˈkliːvɪdʒ/noun
1- a sharp division; a split劈开; 分裂：
a system dominated by the class cleavage.
由阶级分裂主导的制度。
1.1
- the hollow between a woman's breasts when supported, especially as exposed by a low-cut garment（尤指妇女穿低胸衣物露出的）乳沟。
1.2
- mass noun Biology cell division, especially of a fertilized egg cell【生】细胞分裂（尤指受精卵细胞分裂）, 卵裂。
1.3
- mass noun the splitting of rocks or crystals in a preferred plane or direction（岩石、晶体的）解理, 劈理。