derf

Derf \Derf\, a. [Icel. djafr.]
   Strong; powerful; fierce. [Obs.] -- {Derf"ly}, adv. [Obs.]
   [1913 Webster]
    

derf
 /derf/

   [PLATO]

   1. v. The act of exploiting a terminal which someone else has
   absentmindedly left logged on, to use that person's account,
   especially to post articles intended to make an ass of the victim
   you're impersonating. It has been alleged that the term originated as
   a reversal of the name of the gentleman who most usually left himself
   vulnerable to it, who also happened to be the head of the department
   that handled PLATO at the University of Delaware. Compare {baggy
   pantsing}.

   2. n. The victim of an act of derfing, sense 1. The most typical
   posting from a derfed account read "I am a derf.".