The Free On-line Dictionary of Computing (30 December 2018):

Grim File Reaper
GFR

    (GFR) An ITS and LISP Machine
   utility to remove files according to some program-automated or
   semi-automatic manual procedure, especially one designed to
   reclaim mass storage space or reduce name-space clutter (the
   original GFR actually moved files to tape).

   See also prowler, reaper.  Compare GC, which discards
   only provably worthless stuff.

   (1996-06-20)