If two or more things coalesce, they come together and form a larger group or system.
例句
Cities, if unrestricted, tend to coalesce into bigger and bigger conurbations...如果不加限制，城市往往会联合发展成越来越大的集合城市。His sporting and political interests coalesced admirably in his writing about climbing.他在写登山的文章中，把自己对体育和政治的兴趣完美地结合了起来。
英汉词典释义
vi.
联合,合并
The view of party leader coalesce to form a coherent policy.党的领导人的各种观点已统一为一致的政策。