coalitionco·a·li·tion /ˌkəʊəˈlɪʃən◂ˌkoʊə-/ noun1[countableC] a group of people who join together to achieve a particular purposeA coalition of junior doctors, managers, and consultants must assess the working practices of all staff.
2[countableC] two or more political parties that join together to fight an electiona coalition of opposition parties
a coalition government
3[uncountableU] a process in which two or more political parties or groups join together