foul line

noun

1. 1.A line from which a player takes a free throw
2. 2.One of the two lines on the edge of a field marking the area inside which a fair ball may be hit.
3. 3.A line between the lane and the approach, which the bowler must not cross.
4. 4.In long jump, a line before which the jumper must start their jump with no part of the foot touching the line.