Support for the continuance of the United Kingdom (especially with respect to Northern Ireland)
Unionism is any set of political principles based on the idea that two or more political or national units should be joined or remain together, for example that Northern Ireland should remain part of the United Kingdom. + unionist unionists un·ion·ist traditional unionists fearful of home rule. the principles of those people in Northern Ireland, mainly Protestants, who want Northern Ireland to remain as part of the UK. There are several political parties that support these principles, including the Ulster Unionists and the Democratic Unionist Party. belief in the principles of trade unions