noun
Etymology: post (IV) + office
1.
a. : a government department charged with regulating and handling the transmission of mail in a country
in the United States the post office is an executive department and its chief official, the postmaster general, is a member of the president's cabinet
b. : a section of a post office department handling the mail for a particular place (as a city or town)
a list of the post offices of Canada
c.
(1) : a building or a section of a building housing facilities and staff for carrying out all or some of the functions of a post-office department
(2) : a railway car or train or a bus or truck fitted for the sorting of mail in transit
d. : a place where mail is handled for dispatch and delivery
a camp post office
a university post office
2. : a game in which a player acting as postmaster or postmistress may exact a kiss from one of the opposite sex as payment for the pretended delivery of a letter