Definition of fourth-class in English:

fourth-class

adjective

US
  • A class of US mail applying to packages weighing more than sixteen ounces and used especially for sending general merchandise, books, recordings, and films.

    • ‘The ratio of first - to fourth-class mail increased from about 0.085 in 1970 to over 0.20 in 1998, an increase of more than 150 percent.’
    • ‘The fourth-class zone rated parcels and first-class mail have virtually identical historical elasticities.’
    • ‘Bound printed matter is fourth-class mail weighing at least 1 pound but not more than 10 pounds, meet the standards for all fourth-class mail, and be at least 90% advertising.’