Source : Webster's Revised Unabridged Dictionary (1913)

Ineptness \In*ept"ness\, n.
   Unfitness; ineptitude.

         The feebleness and miserable ineptness of infancy.
                                                  --Dr. H. More.

Source : WordNet®

ineptness
     n 1: unskillfulness resulting from a lack of training [syn: {awkwardness},
           {clumsiness}, {ineptitude}, {maladroitness}, {slowness}]
     2: the quality of having the wrong properties for a specific
        purpose [syn: {unsuitability}, {unsuitableness}] [ant: {suitability},
         {suitability}]