The Collaborative International Dictionary of English v.0.48:

Pliant \Pli"ant\, a. [F. pliant, p. pr. of plier to bend. See
   Ply, v.]
   1. Capable of plying or bending; readily yielding to force or
      pressure without breaking; flexible; pliable; lithe;
      limber; plastic; as, a pliant thread; pliant wax. Also
      used figuratively: Easily influenced for good or evil;
      tractable; as, a pliant heart.
      [1913 Webster]

            The will was then ductile and pliant to right
            reason.                               --South.
      [1913 Webster]

   2. Favorable to pliancy. [R.] "A pliant hour." --Shak. --
      Pli"ant*ly, adv. -- Pli"ant*ness, n.
      [1913 Webster]

WordNet (r) 3.0 (2006):

pliantness
    n 1: the property of being pliant and flexible [syn: pliancy,
         pliantness, suppleness]
    2: adaptability of mind or character; "he was valued for his
       reliability and pliability"; "he increased the leanness and
       suppleness of the organization" [syn: pliability,
       pliancy, pliantness, suppleness]