a state of W Germany: formed in 1946 from the S part of the Prussian Rhine province, the Palatinate, and parts of Rhine-Hesse and Hesse-Nassau; part of West Germany until 1990: agriculture (with extensive vineyards) and tourism are important. Capital: Mainz. Pop: 4 059 000 (2003 est). Area: 19 832 sq km (7657 sq miles)