A Catenary

1. (geometry) The curve described by a flexible chain or a rope if it is supported at each end and is acted upon by no other forces than a uniform gravitational force due to its own weight and variations involving additional and non-uniform forces. Catenary - Wikipedia Catenary ring - Wikipedia
2. (engineering) Any physical cable, rope, chain, or other weight-supporting structure taking such geometric shape, as a suspension cable for a bridge or a power-transmission line or an arch for a bridge or roof.
3. (nautical) 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.
4. (transport) A cable, the segments of which between supports take a catenary geometric shape, supporting in turn an overhead conductor that provides trains, trams or trolley buses with electricity, or the combination of the conductor, the cable, and supports.

Synonyms

• (geometry): alysoid, chainette