(military) The line from which soldiers fire their weapons at a target; especially the front line of troops in a battle. / (figuratively) A situation in which someone or something is targeted.

The manager who is directly responsible for an employee.

(aviation) The precise movement of a civil photogrammetric aircraft along a predetermined course at a predetermined altitude during the actual photographic run.

plural of line-out

(UK) a clothesline

(physics) A visual aid for visualizing vector fields; a line drawn such that the direction of its tangent at any point equals the direction of the vector at that point.

(nuclear physics) On the table of nuclides, the limit beyond which an atomic nucleus will immediately decay by emitting a proton or neutron.

(electronics) One of the horizontal lines that compose a raster scanning pattern, as on a television or computer display. / (computing) A single row of pixels in a raster graphics image.

(astronomy) The intersection of an orbiting object's orbital plane with the plane of reference.

Indicates that the telephone line is busy.