Source : Free On-Line Dictionary of Computing

minifloppy
     
         5.25-inch {vanilla} floppy disks, as opposed to
        3.5-inch or {microfloppies} and the now-obsolescent 8-inch
        variety.
     
        At one time, this term was a trademark of {Shugart Associates}
        for their SA-400 minifloppy drive.  Nobody paid any attention.
     
        See {stiffy}.
     
        (1996-05-03)