When you're jacking off and you can't finish so you call in a homie to finish you off.
Yesterday I was jacking off in my room, and I couldn't finish until I had John give me a Vienna Top-off
I met a girl at the bar and later that night I ended up topping off the coolant with her.
A very small meal consumed shortly after a "normal" meal that didn't quite fill you up enough.
Let's stop at a fast food place for a top off meal...just something small. That last meal wasn't quite enough.