Charles Watson-Wentworth char·les·wat·sonwentworth uncommon noun 1. English statesman who served as prime minister and who opposed the war with the American colonies (1730-1782) SynonymsRockinghamSecond Marquis of RockinghamCharles Watson-Wentworth Related words Broader terms statesman WordNet 2.1 (Princeton University). WordNet 2.1 Copyright Princeton University. All rights reserved.