What does the word warn mean?

Usage examples for warn

  1. " Because I saw him with you I wanted to warn you," the woman continued. – The World For Sale, Volume 2. by Gilbert Parker
  2. But it was too late to warn the little boy then. – Daddy Takes Us Skating by Howard R. Garis
  3. I done tried to warn you. – Kildares of Storm by Eleanor Mercein Kelly