What does saltwater mean?
Saltwater is water containing dissolved salt, most commonly the seawater of oceans, bays, and other coastal waters. It is usually treated as an uncountable noun, although “saltwaters” can occasionally refer to distinct bodies or areas of salt water. As an adjective, “saltwater” is commonly written as one word and describes things associated with such water, including saltwater fish, marshes, beaches, and swimming. The word is used in geography, marine biology, cooking, and everyday conversation. It can also distinguish salt water from fresh water, although “freshwater” is more commonly used as the contrasting term in scientific and environmental contexts. Saltwater is central to the study of ocean currents, coastal ecosystems, and the changing salinity of the world’s seas.
Water containing dissolved salt, especially seawater.
"The island’s natural freshwater supply is limited, so residents rely on saltwater for many needs."
Usually uncountable. The plural “saltwaters” is uncommon and may refer to distinct bodies of salt water.
Relating to or consisting of salt water.
"The reef provides an important saltwater habitat for tropical fish."
Usually written as one word when attributive, as in “saltwater habitat” and “saltwater fish.”
Uncommon. Used for distinct bodies or areas of salt water, rather than for the substance in general.
"The study compared the salinity of several coastal saltwaters."
Nearly all the water on Earth is saltwater, making the oceans the planet’s largest connected saltwater system.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Where does saltwater come from?
“Saltwater” is a modern English compound formed from “salt” and “water.” Both elements are inherited from Old English: “salt” developed from the Germanic word for the mineral, while “water” came from Old English wæter. The compound meaning “water containing salt” is recorded in English usage by the early modern period and later became an adjective describing marine environments and objects.
How saltwater is actually used
When used attributively, it is normally written as one word: “saltwater habitat,” “saltwater intrusion.” In technical and environmental contexts, “salt water” may also appear as two words. The adjective use is especially common in terms such as “saltwater fish” and “saltwater marshes.”