1. tv. to jettison something, including a corpse, from a ship at sea. (Usually deep-six as a verb.) They deep-sixed the body of the first mate, who had died of the shakes.
2. and the deep six n. burial at sea. (Always with the in this sense.) I think I’d want the deep six, but I’ll probably kick off on dry land.
3. tv. to kill or dispose of someone. (Underworld. Usually deep-six as a verb.) The thugs tried to deep-six the witness, but failed.
4. tv. to throw something away. (Usually deep-six as a verb.) Take this old thing out and deep-six it.
5. and the deep six n. a grave. (Always with the in this sense. Graves are usually six feet deep.) When you know the deep six is at the end of the line no matter who you are, it makes you take life less seriously.