Source : Webster's Revised Unabridged Dictionary (1913)

Con \Con\, v. t. [imp. & p. p. {Conned}; p. pr. & vb. n.
   {Conning}.] [AS. cunnan to know, be able, and (derived from
   this) cunnian to try, test. See {Can}, v. t. & i.]
   1. To know; to understand; to acknowledge. [Obs.]

            Of muses, Hobbinol, I con no skill.   --Spenser.

            They say they con to heaven the highway. --Spenser.

   2. To study in order to know; to peruse; to learn; to commit
      to memory; to regard studiously.

            Fixedly did look Upon the muddy waters which he
            conned As if he had been reading in a book.
                                                  --Wordsworth.

            I did not come into Parliament to con my lesson.
                                                  --Burke.

   {To con answer}, to be able to answer. [Obs.]

   {To con thanks}, to thank; to acknowledge obligation. [Obs.]
      --Shak.