roux

A mixture of flour and fat cooked together and used as a thickening.

In cookery, a material composed of melted butter and flour, used to thicken soups and gravies.

A thickening, made of flour, for soups and gravies.

A mixture of fat (usually butter) and flour used to thicken sauces and stews.

a mixture of fat and flour heated and used as a basis for sauces