Source : Webster's Revised Unabridged Dictionary (1913)

Inventive \In*vent"ive\, a. [Cf. F. inventif.]
   Able and apt to invent; quick at contrivance; ready at
   expedients; as, an inventive head or genius. --Dryden. --
   {In*vent"ive*ly}, adv. -- {In*vent"ive*ness}, n.

Source : WordNet®

inventiveness
     n : the power of creative imagination [syn: {ingeniousness}, {ingenuity},
          {cleverness}]