Oscar Hammerstein II os·car·ham·mersteinii uncommon noun 1. United States lyricist who collaborated on many musical comedies (most successfully with Richard Rodgers) (1895-1960) SynonymsHammersteinOscar HammersteinOscar Hammerstein II Related words Broader terms lyricist WordNet 2.1 (Princeton University). WordNet 2.1 Copyright Princeton University. All rights reserved.