noun.
The curve described by a flexible chain or a rope if it is supported at each end and is acted upon only by no other forces than a uniform gravitational force due to its own weight.
noun.
The curve of an anchor cable from the seabed to the vessel; it should be horizontal at the anchor so as to bury the flukes.
noun.
A system of overhead power lines that provide trains, trolleys, buses, etc., with electricity, having a straight conductor wire and a bowed suspension cable.