Source : Free On-Line Dictionary of Computing

slopsucker
     
        /slop'suhk-r/ A lowest-priority task that waits around until
        everything else has "had its fill" of machine resources.  Only
        when the machine would otherwise be idle is the task allowed
        to "suck up the slop".  Also called a "hungry puppy" or
        "bottom feeder".  One common variety of slopsucker hunts for
        large prime numbers.  Compare {background}.
     
        [{Jargon File}]