What does the word teens mean?

Usage examples for teens

  1. There were long pants for boys in their late teens, and those came down to their shoe tops. – The-Life-of-Me-an-autobiography by Johnson, Clarence Edgar
  2. Mrs. Lee had suffered many sorrows, and Lucy, although only in her teens, was a comfort who had never failed her. – The Angel Adjutant of "Twice Born Men" by Minnie L. Carpenter