[Zweisamkeit](http://www.duden.de/rechtschreibung/Zweisamkeit) is actually a wordplay on the German word for solitude or lonesomeness: Einsamkeit, which literally means onesomness. Zweisamkeit describes the feeling of being together with someone when no one else is around, often with a romantic connotation. It's almost exclusively used in a positive sense: it's a state of harmony between two people who care for each other. Often in combination with "traut", which can be translated as "intimate", "trusted": "Wir verbrachten den Abend in trauter Zweisamkeit." We spend the evening in intimate togetherness.