Source : Webster's Revised Unabridged Dictionary (1913)

Mesne \Mesne\, a. [Cf. {Mean} intermediate.] (Law)
   Middle; intervening; as, a mesne lord, that is, a lord who
   holds land of a superior, but grants a part of it to another
   person, in which case he is a tenant to the superior, but
   lord or superior to the second grantee, and hence is called
   the mesne lord.

   {Mesne process}, intermediate process; process intervening
      between the beginning and end of a suit, sometimes
      understood to be the whole process preceding the
      execution. --Blackstone. Burrill.

   {Mesne profits}, profits of premises during the time the
      owner has been wrongfully kept out of the possession of
      his estate. --Burrill.