A preserved apple which has lost the majority of its water content and thus appears wrinkled and shriveled. It was a term invented by Shakespeare, not Seth MacFuckingFarlane.
One who amongst your circle of friends is commonly known as a lesser person, often humorously scorned in passing, yet not worthy of lengthy thought.
"Oh look everyone it's Alex Trebek. Hey Alex, ya beef witted apple john! What's the difference between you and a bird with a cold? One's a sick duck...anyways I don't remember how it ends but your mother's a whore."
When after anal sex (with a man or a woman), a man goes to urinate and a little brown "stem" (resembling an Apple Stem) pops out of his penis.
So I fucked this bitch in her dirty asshole last night and when I was done corn holing the broad I went to take a piss and a Johnny Apple Stem popped out!
Wife: What the hell happened to your boxers and pants?
Husband: Your mother's cooking gave me the Johnny Rotten Apple Quicksteps. Those last few steps on the way to the bathroom were brutal. Good thing I was wearing socks.