the situation of two or more people working together to create or achieve the same thing

The two playwrights worked in close collaboration (with each other) on the script. 两位剧作家密切合作编写这个剧本。

The new airport is a collaboration between two of the best architects in the country. 新机场是国内两位顶级建筑师通力合作的成果。

the situation of people working with an enemy who has taken control of their country

She was accused of collaboration. 她被指控通敌。