au

¹ American  

[oh] / oʊ /

French.

plural

aux

1. to the; at the; with the.

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Au ² American  

abbreviation

1. author. Also au

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Au ³ American  

Symbol, Chemistry.

1. gold.

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AU ⁴ American  

abbreviation

1. astronomical unit.

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A.U. ⁵ American  

Or a.u.

abbreviation

1. angstrom unit.

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Au ¹ British  

symbol

1. gold

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AU ² British  

abbreviation

1. African Union

2. Also: a.u..  angstrom unit

3. Also: a.u..  astronomical unit

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au ³ British  

abbreviation

1. Australia

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AU Scientific  

1. Abbreviation of astronomical unit

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Etymology

Origin of Au

From the Latin word aurum

Example Sentences

Writing in a local cafe is not only cheaper—the price of a café au lait—but also offers the illusion of companionship without any of its intrusions.

From The Wall Street Journal • Mar. 27, 2026

Here he is the 1919 go-between for Esther Nacht, a 14-year-old Jewish refugee whom he places with the Winslow family as an au pair.

From Los Angeles Times • Nov. 1, 2025

Coquilles Saint-Jacques is essentially a frou-frou description for scallops au gratin, more often prepared as a casserole than in those magical shells which are harder to find these days.

From Salon • Nov. 1, 2025

Warnings are also in effect parts of Haiti including the capital, Port au Prince, the Dominican Republic and eastern Cuba, where Melissa is anticipated to bring similar effects by the middle of next week.

From BBC • Oct. 26, 2025

“And make the coffee very strong and hot and fill the cups with half coffee and half hot milk and we’ll toast 1918 in café au lait.”

From "A Tree Grows in Brooklyn" by Betty Smith