A Tap

1. A tapering cylindrical pin or peg used to stop the vent in a cask. Synonym: spigot
2. A device used to dispense liquids.Synonyms: faucet, handle, spigot, spout
3. Liquor drawn through a tap; hence, a certain kind or quality of liquor.
4. A place where liquor is drawn for drinking. Synonyms: taproom, bar
5. (mechanics) A device used to cut an internal screw thread. (External screw threads are cut with a die.)
6. A connection made to an electrical or fluid conductor without breaking it.
7. An interception of communication by authority.
8. A device used to listen in secretly on telephone calls. [from 20th c.]
9. (medicine, informal) A procedure that removes fluid from a body cavity. Synonym: paracentesis