collaborate
/kəˈlæbəreɪt; kə`læbəˌret/ v[I, Ipr]
1 ~ (with sb) (on sth) work together (with sb), esp to create or produce sth （与某人）合作; 协作（尤指创造或生产某事物）
She collaborated with her sister/She and her sister collaborated on a biography of their father. 她和姐姐合作写父亲的传记.
2 ~ (with sb) (derog 贬) help enemy forces occupying one's country 通敌; 勾结敌人
He was suspected of collaborating (with the enemy). 怀疑他（与敌人）勾结.