Source : Webster's Revised Unabridged Dictionary (1913)

Evasive \E*va"sive\, a. [Cf. F. ['e]vasif. See {Evade}.]
   Tending to evade, or marked by evasion; elusive; shuffling;
   avoiding by artifice.

         Thus he, though conscious of the ethereal guest,
         Answered evasive of the sly request.     --Pope.

         Stammered out a few evasive phrases.     --Macaulay.
   -- {E*va"sive*ly}, adv. -- {E*va"sive*ness}, n.

Source : WordNet®

evasiveness
     n : intentionally vague or ambiguous [syn: {equivocation}, {prevarication}]