Mad, or stupid.
Welsh slang. The phrase originally comes from the action of having tapped a barrel of beer, draining its contents. The comparison made, then, is between a half-empty barrel of beer and a half-empty brain.
"Watch out for him, he's tapped."
"Are you tapped or what?"
To hit one with the meaty part of your cock.
"Albert, I'm gonna Meat tap Alex."
To hit someone (or something) with your meaty cock.
"I'm going to Meat tap Alex!"
when someone has an excessively large butt available at any moment.
Another way of calling someone stupid
Person: You got the mental complexion of a tap dancing tangerine on a Sunday night drinking a Pina colada
Tapping someone's left shoulder while standing on the right, or vice versa.
Bob just alternative shoulder tapped Susie.