S: (n) foul line (lines through 1st and 3rd base indicating the boundaries of a baseball field)
S: (n) foul line (a line across a bowling alley that a bowler must not cross)
S: (n) foul line (a line from which basketball players take penalty shots)
S: (n) baseline (the lines a baseball player must follow while running the bases)
S: (n) goal line (a line marking each end of the playing field or pitch; where the goals stand)
S: (n) red line (a line that is colored red and that bisects an ice hockey rink)
S: (n) scrimmage line, line of scrimmage (line parallel to the goal lines where football linesmen line up at the start of each play in American football) "the runner was tackled at the line of scrimmage"
S: (n) service line, baseline (the back line bounding each end of a tennis or handball court; when serving the server must not step over this line)