DuckCorp Dico

Found one definition

1.                 From The Devil's Dictionary (1881-1906):
                   
   
   
                   
                     
   R.I.P.  A careless abbreviation of requiescat in pace, attesting to
   indolent goodwill to the dead.  According to the learned Dr. Drigge,
   however, the letters originally meant nothing more than _reductus in
   pulvis_.