a further competition, election, race, etc., after a tie or inconclusive result

he won only 49 per cent of the vote, so a run-off will be held

the draining away of water (or substances carried in it) from the surface of an area of land, a building or structure, etc.

the ratio of run-off to rainfall

fertilizer run-off from the intensively farmed areas in the river basin

a separate area of land where young animals are kept