What does the word both mean?

Usage examples for both

  1. They both of them did as they were told, and they had to do it." – The Box with the Broken Seals by E. Phillips Oppenheim
  2. I am afraid, really afraid it will have to be both. – A Man's Hearth by Eleanor M. Ingram
  3. Call your girl there, and come out both of you as soon as possible!" – The Allis Family; or, Scenes of Western Life by American Sunday School Union