post office 
noun
1The public department or corporation responsible for postal services and (in some countries) telecommunications.The strike is set to halt postal delivery and post office counter service in the London area....
- The council is exploring the option of having a community post office service provided within the village.
- Government still attempts this, with its ridiculous post office and public utility monopolies.
1.1A building where postal business is transacted.When choosing sites for new developments we still place great importance on having a post office and other public amenities nearby....
- I placed my name on a recent letter to the editor about the lousy service at the local post office and I am not sorry that I did.
- The jury heard that the robberies at the service station and the post office were committed within six hours of each other last April.
2 US term for postman's knock.So how do you play Post Office? What are the rules?"...
- I remember playing Post Office, but I don't remember exactly how it worked - it's funny, but I don't remember any of the boys I kissed, either.
- They met, played ‘post office’ on three dates, got married in 1970, and have been together ever since.