Source : Webster's Revised Unabridged Dictionary (1913)

Demy \De*my"\, n.; pl. {Demies}. [See {Demi-}.]
   1. A printing and a writing paper of particular sizes. See
      under {Paper}.

   2. A half fellow at Magdalen College, Oxford. [Written also
      {demi}.]

            He was elected into Magdalen College as a demy; a
            term by which that society denominates those
            elsewhere called ``scholars,'' young men who partake
            of the founder's benefaction, and succeed in their
            order to vacant fellowships.          --Johnson.

Demy \De*my"\, a.
   Pertaining to, or made of, the size of paper called demy; as,
   a demy book.