Lewis & Short

† prŏthyra, ōrum, n., = πρόθυρα.

  1. I. In a Grecian house, the space before the door, the vestibule, Vitr. 6, 10.
  2. II. In a Roman house, a railing or wicket before the door, the Gr. διάθυρα, Vitr. 6, 10.