Merriam-Webster Collegiate Dictionary - rabbet joint

 noun  Date: circa 1828 a joint formed by fitting together rabbeted boards or timbers RABBET  I. noun  Etymology: Middle English rabet, perhaps from Middle French rabat act of forcing down, from Old French rabattre to force down, fold over, reduce — more at rebate  Date: 14th century a channel, groove, or recess cut out of the edge or face of a surface; especially one intended to receive another member (as a panel)  II. verb  Date: 15th century  transitive verb  1. to unite the edges of in a ~ joint  2. to cut a ~ in  intransitive verb to become joined by a ~