2. Gently hit or touch
3. Proceed to sex, fuck
4. A type of spigot head
5. A type of water
2. Johnny tapped the table.
3. Johnny tapped dat ass!!
4. Johnny used a tap on the keg.
5. Johnny drank tap water and tapped dat ass!!
Oh, and there's the sexual definition too, but that has clearly been overdone. :)