Source : Webster's Revised Unabridged Dictionary (1913)

Contractile \Con*tract"ile\, a. [Cf. F. contractile.]
   tending to contract; having the power or property of
   contracting, or of shrinking into shorter or smaller
   dimensions; as, the contractile tissues.

         The heart's contractile force.           --H. Brooke.

         Each cilium seems to be composed of contractile
         substance.                               --Hixley.

   {Contractile vacuole} (Zo["o]l.), a pulsating cavity in the
      interior of a protozoan, supposed to be excretory in
      function. There may be one, two, or more.

Source : WordNet®

contractile
     adj : capable of contracting or being contracted; "the contractile
           wings of an insect"