What does the word herein mean?

Usage examples for herein

  1. Herein lies a great truth and a great error. – The Dollar Hen by Milo M. Hastings
  2. Herein the old nobleman gave a further description of the accident, but the main business of the communication was to ask her if, since he was not as yet very active, she would come to Enckworth Court and delight himself and a small group of friends who were visiting there. – The Hand of Ethelberta by Thomas Hardy