Shortened version of the word penetrate. It is used when referring to entering or opening something. Can be used in a sexual nature.
I'm about to penny (open) a new bottle of wine.
My bus will penny (arrive)the bus stop in five minutes.
Can you penny (go into) the store on your way home from work for some bread?
He was a good penny.
I have reached Penn Station (meaning sexual penetration occured).
I'm headed all the way to Pennsylvania tonight.