The Collaborative International Dictionary of English v.0.48:

Joiner \Join"er\, n.
   1. One who, or that which, joins.
      [1913 Webster]

   2. One whose occupation is to construct articles by joining
      pieces of wood; a mechanic who does the woodwork (as
      doors, stairs, etc.) necessary for the finishing of
      buildings. "One Snug, the joiner." --Shak.
      [1913 Webster]

   3. A wood-working machine, for sawing, plaining, mortising,
      tenoning, grooving, etc.

   Syn: See Carpenter.
        [1913 Webster]

WordNet (r) 3.0 (2006):

joiner
    n 1: a person who likes to join groups
    2: a woodworker whose work involves making things by joining
       pieces of wood