Source : Webster's Revised Unabridged Dictionary (1913)

Capableness \Ca"pa*ble*ness\, n.
   The quality or state of being capable; capability;
   adequateness; competency.

Source : WordNet®

capableness
     n 1: an aptitude that may be developed [syn: {capability}, {potentiality}]
          [ant: {incapability}]
     2: the quality of being capable -- physically or intellectually
        or legally; "he worked to the limits of his capability"
        [syn: {capability}] [ant: {incapability}, {incapability}]