Source : Webster's Revised Unabridged Dictionary (1913)

Horning \Horn"ing\, n.
   Appearance of the moon when increasing, or in the form of a
   crescent. --J. Gregory.

   {Letters of horning} (Scots Law), the process or authority by
      which a person, directed by the decree of a court of
      justice to pay or perform anything, is ordered to comply
      therewith. --Mozley & W.