Hydronym

A hydronym (from Greek: ὕδρω, hydrō, "water" and ὄνομα, onoma, "name") is a type of toponym that designates a proper name of a body of water. Hydronyms include the proper names of rivers and streams, lakes and ponds, swamps and marshes, seas and oceans. For example, the hydronym for the easternmost lake of the Great Lakes is Lake Ontario. As a subset of toponymy, a distinctive discipline of hydronymy (or hydronomastics) studies the proper names of all bodies of water, the origins and meanings of those names, and their development and transmission through history.