Source : Webster's Revised Unabridged Dictionary (1913)

Ascendancy \As*cend"an*cy\, Ascendance \As*cend"ance\, n.
   Same as {Ascendency}.

Source : WordNet®

ascendancy
     n : the state that exists when one person or group has power
         over another; "her apparent dominance of her husband was
         really her attempt to make him pay attention to her"
         [syn: {dominance}, {ascendance}, {ascendence}, {ascendency},
          {control}]