U.S. Code / Title 21 — Food and Drugs / Chapter 9—Federal Food, Drug, and Cosmetic…Title 21SubchapterSubchapter Ii—DefinitionsContents§ 321. Definitions; generally§ 321a. "Butter" defined§ 321b. "Package" defined§ 321c. Nonfat dry milk; "milk" defined§ 321d. Market names for catfish and ginseng