Source : Webster's Revised Unabridged Dictionary (1913)

Ampleness \Am"ple*ness\, n.
   The state or quality of being ample; largeness; fullness;
   completeness.

Source : WordNet®

ampleness
     n 1: the property of being more than sufficient; comfortable
          sufficiency; "the ampleness of her servings more than
          satisfied his hunger"
     2: the property of impressive largeness in size; "he admired
        the ampleness of its proportions"