1. the state of being split or cleft;

   "there was a cleavage between the liberal and conservative members"
   

2. the breaking of a chemical bond in a molecule resulting in smaller molecules

3. (embryology) the repeated division of a fertilised ovum

4. the line formed by a groove between two parts (especially the separation between a woman's breasts)

5. the act of cleaving or splitting

1.(尤指女子穿低胸服时露出的)乳沟
A woman'scleavage is the space between her breasts, especially the top part which you see if she is wearing a dress with a low neck.

2.裂痕;裂隙;分歧
Acleavage between two people or things is a division or disagreement between them.

e.g. ...the economic cleavages between the two regions.
那两个地区之间的经济差距

1.

1. 卵裂：而是软体动物还出现了横纹肌(striated muscle)与平滑肌(sm-ooth在行有性生殖的后生动物中,生殖细胞的形成也就是精子(sperm)及卵子(ovum)的形成,这一过程是在亲本的生殖腺中进行.由生殖腺上皮形成1.卵裂(cleavage)卵受精后很快即开始细胞分裂,

2. 裂解：HSP70还能通过其他方式干扰凋亡,如阻断Apaf1的形成、增强bcl2的表达等. 在脑缺血再灌注损伤模型中,过表达HSP70的转基因小鼠的细胞色素C释放减少、Apaf1分离、caspase9的裂解(cleavage)减少,从而实现对脑组织的保护作用[21].