The Collaborative International Dictionary of English v.0.48:

Pan \Pan\, v. t. [imp. & p. p. Panned; p. pr. & vb. n.
   Panning.]
   1. (Mining) To separate, as gold, from dirt or sand, by
      washing in a kind of pan. [U. S.]
      [1913 Webster]

            We . . . witnessed the process of cleaning up and
            panning out, which is the last process of separating
            the pure gold from the fine dirt and black sand.
                                                  --Gen. W. T.
                                                  Sherman.
      [1913 Webster]

   2. To criticise (a drama or literary work) harshly.
      [PJC]

The Collaborative International Dictionary of English v.0.48:

panning \pan"ning\, n.
   The act or process in which heavier ores are concentrated by
   agitating a sample of crushed ore under water in a shallow
   pan, thus washing away the lighter particles from the sample;
   as, panning for gold. See pan[1], v. t. and pan[1], v. i.
   [PJC]

Moby Thesaurus II by Grady Ward, 1.0:

45 Moby Thesaurus words for "panning":
   banter, bantering, booing, catcalling, chaffing, derision,
   derisive, derisory, fleering, flippancy, flippant, fooling,
   grinning, hissing, hooting, jeering, joshing, kidding, leering,
   levity, mockery, mocking, quizzical, ragging, railing, raillery,
   rallying, razzing, ridicule, ridiculing, roasting, scoffing, smart,
   smart-aleckiness, smart-alecky, smart-ass, smartness, smirking,
   sneering, snickering, sniggering, snorting, taunting, teasing,
   twitting