Source : Webster's Revised Unabridged Dictionary (1913)

Gradualness \Grad"u*al*ness\, n.
   The quality or state of being gradual; regular progression or
   gradation; slowness.

         The gradualness of this movement.        --M. Arnold.

         The gradualness of growth is a characteristic which
         strikes the simplest observer.           --H. Drummond.

Source : WordNet®

gradualness
     n 1: the property possessed by a slope that is very gradual [syn:
           {gentleness}] [ant: {abruptness}]
     2: the quality of being gradual or of coming about by gradual
        stages [syn: {graduality}]