Definition of postal service in US English:

postal service

noun

US
  • The public department or corporation responsible for mail services and (in some countries) telecommunications.

    • ‘Because you cannot rely on the postal service to deliver regular mail in just one or two days, mail your check as early as possible to make sure the vendor receives it before the due date.’
    • ‘If the weather is unusually bad, the postal service can deny shipment, according to regulations.’
    • ‘Interestingly enough, because the headquarters is considered international territory, the United Nations has its own safety forces and postal service.’
    • ‘Nine of these cards were returned to him by the postal service for one reason or another.’
    • ‘The Department of Justice found the four not by tracking IP addresses but by following a paper trail through the postal service.’