Sl. to get rid of someone or something; to dispose of someone or something. (Refers originally to burying someone or something six feet deep, the standard depth of a grave.) Take this horrible food out and deep-six it.That guy is a pain. Deep-six him so the cops will never find him.
deep-six somebody/something
(American informal)
to get rid of someone or something They want to deep-six the project because it's costing too much money.