1. Deep distress, sadness, or regret especially for the loss of someone or something loved.
  2. The resultant unhappy or unpleasant state.
  3. A cause of grief or sadness.
  4. A display of grief or sadness.
  5. (verb) To feel or express sorrow.

The emotion of Sorrow is found in the Small Intestine meridian in the Fire element.

Definition from Dictionary by Merriam-Webster.