The Collaborative International Dictionary of English v.0.48:

counterclockwise \coun"ter*clock"wise\ adj. & adv.
   in the opposite direction to that in which the hands of a
   clock rotate, as viewed from in front of the clock face; --
   of rotatory motion or spiral direction. Opposite of
   clockwise, or right-handed

   Note: [Narrower terms: sinistral levororotary,
         levorotatory]

   Syn: left-handed.
        [PJC]