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• roux
  roux

  noun

  a cooked mixture of butter or other fat and flour used to thicken sauces, soups, etc.
• Roux
  Roux

  French bacteriologist who assisted Louis Pasteur on most of his major discoveries. Later, working with Alexandre Yersin, he showed that the symptoms of diphtheria are caused by a lethal toxin produced by the diphtheria bacillus. Roux carried out early work on the rabies vaccine and directed the first tests of the diphtheria antitoxin.

roux

American  

[roo] / ru /

noun

1. a cooked mixture of butter or other fat and flour used to thicken sauces, soups, etc.

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roux British  

/ ruː /

noun

1. a mixture of equal amounts of fat and flour, heated, blended, and used as a basis for sauces

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Roux Scientific  

/ ro̅o̅ /

1. French bacteriologist who assisted Louis Pasteur on most of his major discoveries. Later, working with Alexandre Yersin, he showed that the symptoms of diphtheria are caused by a lethal toxin produced by the diphtheria bacillus. Roux carried out early work on the rabies vaccine and directed the first tests of the diphtheria antitoxin.

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Etymology

Origin of roux

1805–15; < French ( beurre ) roux brown (butter) < Latin russus red-brown, red-haired, akin to ruber red ¹

Explanation

A roux is the base of many sauces, made by combining and cooking flour with some kind of fat. If you're making a Cajun recipe, your roux might be a mixture of flour and bacon fat. Cheese sauces, gravies, and staples of French cuisine like Béchamel sauce all begin as a roux. For most roux, you start by heating butter, oil, or another fat in a pan, then add flour and cook it while stirring or whisking until it's completely incorporated and there's no lingering taste of raw flour. Other ingredients, like milk, cream, cheese, or water, are added slowly to the roux. In French, roux means both "browned butter" and "reddish-brown."

Example Sentences

See Examples For:

roux Roux

Once I learned what a roux was, I wanted every meal to have one.

From Salon ● Jul. 28, 2026

Doesn’t matter if it’s caramel, some sort of roux or queso, I’m always hunched over a hot pot stirring my wrist off, testing and adding until it tastes perfect.

From Seattle Times ● May 14, 2024

Rather boringly brown in presentation, the gumbo gets velvety from a luxe roux, echoing smoke, faint heat and stages of flavor, with all the tastes and texture of the sausage incorporated through.

From Seattle Times ● Jul. 26, 2023

You'll only need about a cup of roux in this recipe, so you can freeze leftover roux in an airtight container to use later.

From Salon ● May 18, 2023

Thin the roux with a little soup, so it will be smooth before adding it to the soup kettle.

From The Century Cook Book by Mary Ronald

During the podcast episode, the BBC correspondent Anoushka Mutanda Dougherty asks if she can see the direct-message exchange between An and La Roux.

From Los Angeles Times ● Jun. 11, 2026

In 2024, An got back in touch with La Roux via a direct message on Instagram asking if she remembered the alleged incident.

From BBC ● Jun. 10, 2026

Macquarie calls Le Roux a pair of “safe hands operationally,” as one of the miner’s most experienced executives.

From The Wall Street Journal ● Jun. 5, 2026

Le Roux and team highlight the potential for a swing back toward large caps because institutional investors tend to be “value-driven and slow-moving,” so overweighting the cheaper small cap index was unavoidable.

From MarketWatch ● May 5, 2026

The owner lured Roux away with a shriveled pig’s ear, which is apparently a canine delicacy?

From "From Twinkle, with Love" by Sandhya Menon