A term used to refer to someone or something that performs two roles. The new EU army units will serve both NATO and the EU under a double command system.
The term is also used to describe the EU's foreign minister (“High representative”) being appointed by the European Council and at the same time being vice-president of the European Commission.
It was prohibited in most of the member states to have a seat in the European Parliament as well as in a national parliament. From 2009 onwards this has been prohibited in all member states.