1. Dutch: from the Germanic personal name Razo, a derivative of compound names with the first element rād ‘counsel’.
2. German: from an old field name, ros, ras, meaning ‘swamp’. There is a stream called Rase near Göttingen, which may also be a source of the surname.
3. German: from a short form of the personal name Erasmus (see Rasmus), or from a short form of a Slavic personal name with the first element rad. Compare Rasch 2.
4. South German (Räse): variant of Rass or Räss (see Ras 6).
See the Key to the Dictionary or consult the General Introduction for further explanation.