What does the word postern mean?

Usage examples for postern

  1. On one side of the courtyard is a postern, which was thrown open when the royal cavalcade had entered the grounds by the lodge gate. – Memoirs of James Robert Hope-Scott, Volume 2 by Robert Ornsby
  2. The door that the girl had locked was the only one that connected the postern hail with the castle. – Otto of the Silver Hand by Howard Pyle
  3. Gliding forward, I peep'd out at the postern gate; but drew back like a shot. – The Splendid Spur by Arthur T. Quiller Couch