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]

Moby Thesaurus II by Grady Ward, 1.0:

23 Moby Thesaurus words for "puttering":
   coquetry, dabbling, dalliance, dallying, fiddling, flirtation,
   fooling, fooling around, idling, jerking off, kidding around,
   loitering, messing around, monkeying, monkeying around, piddling,
   playing, playing around, pottering, smattering, tinkering, toying,
   trifling