(shipbuilding) the outline of a horizontal section of a vessel, as when floating in the water.

(physics) any of a series of dark lines in the solar spectrum; due to the absorption of light by atoms and molecules in the Sun's atmosphere

(parachuting) The cord attached from the parachute pack to the plane, used to automatically deploy the parachute.

(idiomatic) A clear distinction in the context of a legal or moral judgment.

(nautical) Properly the International Load Line, a mark on the hull of a merchant ship to show the waterline under specified conditions. The line shows the maximum capacity load the ship may carry.

(physics) An imaginary line in a field of force, whose tangent at any point gives the direction of the field at that point and whose number through unit area perpendicular to the field represents its intensity.

A straight line along which an observer has a clear view. / (weaponry) The line which passes through the front and rear sight, at any elevation, when they are sighted at an object.

(mathematics) A logarithmic line on a Gunter's scale, which is used to perform the multiplication and division of numbers mechanically with only dividers.

(American football, Canadian football) The five players comprising the center, the left and right offensive guards, and the left and right offensive tackles who are positioned around the ball at the line of scrimmage.

(idiomatic) To overstep a boundary, rule, or limit; to go too far or do something unacceptable. / To finish a race. / To achieve completion of something. / To cross the equator, as a vessel at sea.