1N-COUNT (尤指女子穿低胸服时露出的)乳沟 A woman's cleavage is the space between her breasts, especially the top part which you see if she is wearing a dress with a low neck. (尤指女子穿低胸服时露出的)乳沟
2N-COUNT 裂痕;裂隙;分歧 A cleavage between two people or things is a division or disagreement between them. 裂痕;裂隙;分歧 [formal]
...the economic cleavages between the two regions.