The Collaborative International Dictionary of English v.0.48:

Putter \Put"ter\, n.
   1. One who puts or plates.
      [1913 Webster]

   2. Specifically, one who pushes the small wagons in a coal
      mine, and the like. [Prov. Eng.]
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Putter \Putt"er\, n. (Golf)
      (a) A club with a short shaft and either a wooden or a
          metal head, used in putting.
      (b) One who putts.
          [Webster 1913 Suppl.]

The Collaborative International Dictionary of English v.0.48:

Putter \Put"ter\, v. i. [imp. & p. p. Puttered; p. pr. & vb.
   n. Puttering.] [See Potter.]
   To act inefficiently or idly; to occupy oneself in a
   liesurely manner; to trifle; to potter; as, to putter around
   in the garden.
   [1913 Webster +PJC]

WordNet (r) 3.0 (2006):

putter
    n 1: a golfer who is putting
    2: the iron normally used on the putting green [syn: putter,
       putting iron]
    v 1: work lightly; "The old lady is pottering around in the
         garden" [syn: potter, putter]
    2: do random, unplanned work or activities or spend time idly;
       "The old lady is usually mucking about in her little house"
       [syn: putter, mess around, potter, tinker, monkey,
       monkey around, muck about, muck around]
    3: move around aimlessly [syn: putter, potter, potter
       around, putter around]