What is the meaning of the word "tap"?

Definitions:

dance and make rhythmic clicking sounds by means of metal plates nailed to the sole of the dance shoes verb
- Glover tapdances better than anybody
draw (liquor) from a tap verb
- tap beer in a bar
draw from or dip into to get something verb
- tap one's memory
furnish with a tap or spout, so as to be able to draw liquid from it verb
- tap a cask of wine
make light, repeated strikes on a surface verb
- I was tapping my fingers on the table impatiently.
pierce in order to draw a liquid from verb
- tap a maple tree for its syrup
strike lightly verb
- They tapped me on the shoulder.
tap a telephone or telegraph wire to get information verb
- The FBI was tapping the phone line of the suspected spy