Roux

Pronounced: 'rue'

Roux is a mixture of flour and fat, typically lard, butter or oil.  It is used to thicken gumbos and other stew-like dishes common to Creole or French cooking.  The rule of thumb is that the darker the roux, the less thickening power it has.  Most often when asked about making a Creole dish, one would reply "Well, first you make a roux".