The Collaborative International Dictionary of English v.0.48:

Serpentize \Ser"pent*ize\, v. i.
   To turn or bend like a serpent, first in one direction and
   then in the opposite; to meander; to wind; to serpentine.
   [R.]
   [1913 Webster]

         The river runs before the door, and serpentizes more
         than you can conceive.                   --Walpole.
   [1913 Webster]