- Baseball either of the lines extending from home plate through the outside corners of first base or third base and onward to the end of the outfield
- Basketball a free-throw line
- Tennis, Bowling, etc. any of various lines bounding the playing area, outside of which the ball must not be hit, the player must not go, etc.
See foul line in American Heritage Dictionary 4
- Baseball Either of two straight lines extending from the rear of home plate to the outer edge of the playing field and indicating the area in which a fair ball can be hit.
- Basketball A line 15 feet in front of each backboard from which players shoot foul shots. Also called free-throw line.
- Sports A boundary limiting the permissible movements of a player, as on a bowling alley or in a field event.