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]

Moby Thesaurus II by Grady Ward, 1.0:

46 Moby Thesaurus words for "putter":
   beguile the time, burn daylight, consume time, coquet, dabble,
   dally, diddle, doodle, fiddle, fiddle with, fiddle-faddle,
   fidget with, finger with, flirt, fool, fool around, fool with,
   footle, fribble, fritter away time, frivol, horse around, idle,
   jerk off, kid around, kill time, loiter, lose time, mess,
   mess around, monkey, monkey around, pass the time, piddle, play,
   play around, play with, potter, puddle, smatter, tinker, toy,
   toy with, trifle, twiddle, waste time