= M =
mouse droppings n.
[MS-DOS] Pixels (usually single) that
are not properly restored when the mouse pointer moves away from a
particular location on the screen, producing the appearance that
the mouse pointer has left droppings behind. The major causes for
this problem are programs that write to the screen memory
corresponding to the mouse pointer's current location without
hiding the mouse pointer first, and mouse drivers that do not quite
support the graphics mode in use.
--The Jargon File version 4.3.1, ed. ESR, autonoded by rescdsk.