The act of defiling the food of another person, often as an act of revenge. In most cases fishpickling can only be done by a male, but the term can be used in a broader context.
I got wise with the guy taking my order and I think he fishpickled my sandwich when I wasn't looking.
Everyone: Do you like fish sticks?
Kanye West: Yeah
Everyone: Do you like putting fishdicks in your mouth?
Kanye West: Yeah
Everyone: What are you, a gay fish?!?!?
the correct way to order a fish sandwich in any fish and chip shop. A fish sandwich is a buttered breadcake with a heavily battered fish (normally cod or haddock (or even the sick combination: CODDOCK)) inside, oozing grease.
Harry: "One fishwich please Squire!"
George: "Yes, very good sir."
Harry: "Cod if you would please, i can't stand that bastardin' bastard Haddock."