(n): a basis for comparison; a reference point against which other things can be evaluated
(n): the back line bounding each end of a tennis or handball court; when serving the server must not step over this line
(n): in games or sports; a mark indicating positions or bounds of the playing area
(n): the lines a baseball player must follow while running the bases
(n): in games or sports; a mark indicating positions or bounds of the playing area
