hydronym

noun

the name of a body of water (such as a lake or river)

What does hydronym mean?

Hydronym refers to the name of a body of water (such as a lake or river). Examples include Cape Fear and Mono Lake.

Examples of hydronym

The name Lake Ontario comes from the Wendat word Ontari’io, which, appropriately, means “the lake is beautiful, the lake is big”. … We know that America is changing. Their trading relationships, their foreign policies, their national monuments, their hydronyms.
—Canadian Prime Minster Mark Carney (@MarkJCarney), X (formerly Twitter, 27 Aug. 2026

The cartographic history of this stream also evidences an unbroken chain of development leading from the original French hydronym to the English one.
—Michael McCafferty, Names, June 2003

It is of course exciting to think of an archaic hydronym on the edge of Scotland, going back to a Bronze Age people who spoke some unknown non-Indo-European language.
—Andrew Breeze, Scottish Language, 1 Jan. 2006

Where does hydronym come from?

Hydronym appears to have arisen in the mid-20th century, according to current evidence, and combines hydr- (“water”) and -onym (“word, name”).

How is hydronym used?

Interest in the word hydronym spiked in August of 2026 after Canadian prime minister Mark Carney used it in an online post referencing the changing (in the United States) of one of the Great Lakes by Donald Trump. Up until that point, hydronym mostly appeared in print in academic publications focused on subjects including linguistics, cartography, etc. It is not a common enough word (yet) to meet our criteria for entry, but hydronymy (“names of bodies of water”) is entered in our Unabridged dictionary.