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.

A cultural and aesthetic mind-state that prioritizes making money, even as an “underground” or “radical” creator. The work isn’t made for money, but it’s the money that matters the most.

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

To deep-six means to get rid of, to ignore, or to bury something. It comes from the six feet depth of a grave.

The six refers to a grave, as in six feet under.
The deep refers to the ocean.

Together we have a death at sea, where youre grave is much futher down than 6 ft. Today we just use it to say "throw away" or something like that.

What a Japenese man dreams he could give a woman

Blowing a load inside a pussy.