roo / roux / rue are similar-sounding terms with different meanings (referred to as homophones). To better understand the differences, see below for definitions, pronunciation guides, and example sentences using each term. 👇
roo: NA
roux: (noun) a mixture of fat and flour heated and used as a basis for sauces.
rue: (noun) European strong-scented perennial herb with grey-green bitter-tasting leaves; an irritant similar to poison ivy. (noun) leaves sometimes used for flavoring fruit or claret cup but should be used with great caution: can cause irritation like poison ivy. (noun) (French) a street or road in France.
roo: NA
roux: r·UW
rue: r·UW
(Examples are Wikipedia snippets under the CC ShareAlike 3.0 license. Definitions drawn from WordNet.)