What does the word therein mean?

Usage examples for therein

  1. We'll also find out what kind of fish can be caught therein. – Dawson Black: Retail Merchant by Harold Whitehead
  2. Likewise, so long as our hearts are kept warm by the rays of God's love shining therein, our pure moral state is easily maintained; but when we lose the warmth of that love, lower things begin to attract us and soon we fall down toward the former level. – Heart Talks by Charles Wesley Naylor
  3. He seemed to present a perpetual apology to the world for his own existence therein. – The Nest of the Sparrowhawk by Baroness Orczy