The Collaborative International Dictionary of English v.0.48:

Comprehensor \Com`pre*hen"sor\, n.
   One who comprehends; one who has attained to a full
   knowledge. [Obs.]
   [1913 Webster]

         When I shall have dispatched this weary pilgrimage, and
         from a traveler shall come to be a comprehensor,
         farewell faith and welcome vision.       --Bp. Hall.
   [1913 Webster]