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

Origin of roux

1805–15; < French (beurre) roux brown (butter) < Latin russus red-brown, red-haired, akin to ruber red1 Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for roux

Contemporary Examples of roux

Historical Examples of roux

  • All structure, according to Roux, is either functional or non-functional.

    Form and Function

    E. S. (Edward Stuart) Russell

  • Roux continued for many years to follow up this line of work.

    Form and Function

    E. S. (Edward Stuart) Russell

  • A vital quality is for Roux a special process or mode of assimilation.

    Form and Function

    E. S. (Edward Stuart) Russell

  • When the sauce is strained, remove the roux from the fire; stir in the sauce.

    The Cauliflower

    A. A. Crozier

  • In 1774, the two children of Roux, a Calvinist of Nimes, are carried off.

British Dictionary definitions for roux


noun plural roux

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

Word Origin for roux

C19: from French: brownish, from Latin russus russet
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Word Origin and History for roux

sauce made from browned butter or fat, 1813, from French (beurre) roux "browned (butter)," from roux "red, reddish-brown," from Latin russus (see russet).

Online Etymology Dictionary, © 2010 Douglas Harper

roux in Medicine


[rōō]Pierre Paul Émile 1853-1933

French bacteriologist. His work with the diphtheria bacillus led to the development of antitoxins to neutralize pathogenic toxins.


Wilhelm 1850-1924

German anatomist who is noted for his research on embryonic development.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.

roux in Science


[rōō](Pierre Paul) Émile 1853-1933

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.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.