United Kingdomer

theoritically it should be the adjective related to United Kingdom. Sometimes an English person is referred to as an Englander, a Scottish as a Scotlander. so a person from United Kingdom can be referred to as "United Kingdomer"

an English person is referred to as an Englander, a Scottish as a Scotlander. so a person from United Kingdom can be referred to as "United Kingdomer"