from Wiktionary, Creative Commons Attribution/Share-Alike License
- proper n. An agreement between 24 countries in Europe, allowing people to cross the borders without a passport and checking their ID card. Thus the old buildings on the borders are no longer in use, therefore on the borders of lots of old members of the agreement you can't see anything else, but a common EU-state sign welcoming the visitor.
From Schengen, the town in Luxembourg where the agreement was made and ratified. (Wiktionary)