- an office or station of a government postal system at which mail is received and sorted, from which it is dispatched and distributed, and at which stamps are sold or other services rendered. Abbreviations: PO, P.O.
- the department of a government charged with the transportation of mail.
- an old-fashioned game in which one player is designated “postmaster” or “postmistress” and calls another player of a different gender into an adjoining room, ostensibly to receive a letter but actually to receive a kiss.
- a building or room where postage stamps are sold and other postal business is conducted
- a government department or authority in many countries responsible for postal services and often telecommunications
