This is a symbol for crying: tears well up in your eyes, move down your cheeks, are only half stopped by your mouth and then run off your chin.

EXAMPLE

The river flowed forcefully, when the rains were heavy, and overflowed its banks and travelled down into the valley to the small lake that resided there; the parched little pond only stopped a small amount of the deluge, the rest would flow into the long grass and disappear, seeming to fall right off the edge of the earth