Source : Webster's Revised Unabridged Dictionary (1913)

Pornography \Por*nog"ra*phy\, n. [Gr. ? a harlot + -graphy.]
   1. Licentious painting or literature; especially, the
      painting anciently employed to decorate the walls of rooms
      devoted to bacchanalian orgies.

   2. (Med.) A treatise on prostitutes, or prostitution.

Source : WordNet®

pornography
     n : creative activity (writing or pictures or films etc.) of no
         literary or artistic value other than to stimulate sexual
         desire [syn: {porno}, {porn}, {erotica}, {smut}]

Source : Free On-Line Dictionary of Computing

pornography
     
         Still or moving images, usually of women, in
        varying states of nudity, posing or performing erotic acts
        with men, women, animals, machines, or other props.  Some say
        it degrades women, some say it corrupts young boys (who
        down-load it from the {World-Wide Web} or exchange it on
        {floppy disks}).  Most of it is in the form of {JPEG} images.
        There are many sites on the {World-Wide Web} offering porn of
        all sorts, almost always for a subscription.  It is said that
        these are a driving force in the evolution of new technology
        and techniques for the web.  Advertisments for them certainly
        constitute a significant proportion of all {spam}.  There are
        even pornographic computer games, an early example being {Mac
        Playmate}.
     
        Beware - many institutions, particularly universities, have
        strict rules against their computers and networks being used
        to transfer or store such things, and you might get corrupted.
     
        (2002-03-08)