To hide or dispose of something in such a way that it will be extremely difficult or impossible to find or recover, even for the person doing the hiding. Get rid of. Nautical in origin, it comes from a call indicating a depth of six fathoms (over ten meters), a depth from which recovery of an item tossed overboard would be very difficult.
Argggh, matey! Deep six the crack pipe before Admiral Billy-Bob catches us.
Jimmy-Joe, we'd better deep six the whole meth kitchen before Andy Taylor shows up at the trailer park
to stow something away in place where it will be impossible to find. the six refers to six fathoms (or 36 feet), the minimum legal depth for a burial at sea
Friend: You fucked that bitch last night right?
You: Yeah, I blew that shit up.
Friend: Did you use a rub?
You: Fuck no. Rubbers are for pussies. In fact I deep six'd that shit.
By Ella
Deep-six
When you have to throw something overboard. Typically when something is on fire.
Derek: Nice plasma tv tom, what did you do with your old console television?
Tom: Oh, I just got back from the landfill, I deep sixed that bitch.
Derek: Nice.