Sentence:  Shea , the chairman of <WSD>Mayor</WSD> Wagner 's Baseball Committee , will be joined on the dais by Warren Spahn , the southpaw pitching ace of the Milwaukee Braves ; Frank Graham , the Journal-American sports columnist ; Bill Mazeroski , the World Series hero of the Pittsburgh Pirates , and Casey Stengel , the former manager of the Yankees . 
Meaning of the word marked with <WSD> tags:  any number of entities (members) considered as a unit