free movement, n.All

Free movement (n.) across ⁠​‌​​​‌​​​‌​‌‌​​​​‌​‌​​‌‌​‌​​‌​​​​​‌‌​​‌​​​‌‌​‌‌​⁠borders was, for Adam Smith, an essential part of free trade — the principle the free traders forget first.