What does the word iron mean?

Usage examples for iron

  1. The lion keeps My iron hills. – By Veldt and Kopje by William Charles Scully
  2. He turned about, and struck the key sharply on the iron door. – Checkmate by Joseph Sheridan Le Fanu
  3. At once he perceived a long, double row of clean white- painted iron beds, on which lay or sat figures of men. – The Blazed Trail by Stewart Edward White