Source : Webster's Revised Unabridged Dictionary (1913)

Illegitimation \Il`le*git`i*ma"tion\, n.
   1. The act of illegitimating; bastardizing.

   2. The state of being illegitimate; illegitimacy. [Obs.]

            Gardiner had performed his promise to the queen of
            getting her illegitimation taken off. --Bp. Burnet.