What does eau mean?
Eau is a noun borrowed directly from French, where it simply means water. In English it survives almost exclusively within fixed French phrases rather than as an ordinary word in its own right. The most familiar examples come from the world of fragrance — eau de Cologne, eau de toilette, and eau de parfum denote scents of increasing concentration — while eau de vie refers to a clear fruit brandy. Because of these associations, the word carries an air of elegance and luxury, and it is often retained untranslated precisely for that continental flair. The plural form is eaux, seen chiefly in perfume branding. Though rare outside these expressions, eau offers a small window into how English absorbs vocabulary: instead of taking the everyday French word for water into general use, it kept only the refined contexts in which French culture lent it prestige. Its ultimate root is the Latin aqua, the same source behind English words like aquatic and aqueduct.
nounA word adopted from French meaning water, used almost exclusively in English within fixed French phrases such as 'eau de Cologne' and 'eau de toilette', or as a component of perfume names.
- Water, as used in fixed French borrowings such as eau de Cologne, eau de toilette, and eau de vie.
- A fragrance or scent product, by extension of the above (as in naming perfumes of varying strength).
"She dabbed on a light eau de toilette before leaving for the evening."
"He splashed on some eau de Cologne after shaving."
"The distillery is famous for its clear eau de vie made from Williams pears."
The plural eaux follows French orthography and appears mostly in perfume terminology and brand names rather than in ordinary prose.
"The boutique stocks eaux from several independent perfumers."
English never really borrowed the word for water — it borrowed the fancy French labels that come wrapped around it, which is why your bathroom shelf speaks more French than you do.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Etymology of eau
Eau comes from Old French eaue, descended from the Latin aqua, meaning water. The regular sound changes that shaped French turned the Latin word into something quite different from its ancestor, yet the Latin root remains visible across Romance languages and in English borrowings such as aquatic, aquarium, and aqueduct, which come directly from Latin rather than through French. English adopted eau in set phrases like eau de Cologne, named for the German city of Cologne where the fragrance originated.
Related word forms
How eau is actually used
In English, eau is essentially never used as a standalone common noun; it appears only inside loan phrases from French, which are typically italicized or treated as set expressions. It carries a refined, somewhat luxurious connotation thanks to its association with perfumery and spirits. The plural eaux occurs mainly in brand names and perfume terminology.
Easily confused with eau
An ewe is a female sheep, whereas eau means water; the two differ in pronunciation (/juː/ versus /oʊ/) despite both having an unusual spelling.
'Owe' means to be under obligation to pay or repay and sounds identical to eau, but it is an unrelated verb.