Definition of line-out:
(n) :
A path through two or more points (compare ‘segment’); a continuous mark, including as made by a pen; any path, curved or straight.
(n) :
(geometry) An infinitely extending one-dimensional figure that has no curvature; one that has length but not breadth or thickness.
(n) :
(geometry, informal) A line segment; a continuous finite segment of such a figure.
(n) :
(graph theory) An edge of a graph.
(n) :
(geography) A circle of latitude or of longitude, as represented on a map.
(n) :
(geography, 'the line' or 'equinoctial line') The equator.