give (someone or something) the deep six

1. To bury someone at sea. Likely a reference to six fathoms of water being the standard depth at which to bury bodies at sea. I'm been a sailor all my life, so when my time comes, please give me the deep six out in the Pacific. We were all worried that huge storm would give us the deep six. I mean, we were just out there in a little sailboat! He's a proud retired Marine, that's why he wants us to give him the deep six when he passes away.

2. To kill someone. A reference to the standard six-foot depth of a grave. I'm starting to fear that the mob may have given our key witness the deep six. We all need to make the most of the time we're given. Something—be it illness, accidents, whatever—will give us the deep six eventually. If you tell anyone, especially the police, what you saw here today, know that we'll give you the deep six, got it?

3. To reject, dispose of, or eliminate (someone or something). The studio gave the film the deep six after its budget began getting out of hand. Management gave our new department head the deep six after it came to light that she had lied about her qualifications. After nearly 30 years of service, we need to give the fabled warship the deep six. The time has come.