The Collaborative International Dictionary of English v.0.48:

Tacksman \Tacks"man\, n.; pl. Tacksmen. (Scots Law)
   One who holds a tack or lease from another; a tenant, or
   lessee. --Sir W. Scott.
   [1913 Webster]

         The tacksmen, who formed what may be called the
         "peerage" of the little community, must be the
         captains.                                --Macaulay.
   [1913 Webster]