The Collaborative International Dictionary of English v.0.48:

Tinker \Tink"er\, v. t. [imp. & p. p. Tinkered; p. pr. & vb.
   n. Tinkering.]
   To mend or solder, as metal wares; hence, more generally, to
   mend.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Tinkering \Tink"er*ing\, n.
   The act or work of a tinker.
   [1913 Webster]

Moby Thesaurus II by Grady Ward, 1.0:

23 Moby Thesaurus words for "tinkering":
   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, puttering, smattering, toying,
   trifling