'deep-six' definitions:

Definition of 'deep-six'

(from WordNet)
verb
Toss out; get rid of; "deep-six these old souvenirs!" [syn: deep-six, give it the deep six]
verb
Throw from a boat [syn: deep-six, throw overboard]

Definition of 'deep-six'

From: GCIDE
  • deep-six \deep-six\ v. t.
  • 1. to discard in a deep body of water; -- also used figuratively, to discard contemptuously.
  • Syn: deep six, give it the deep six. [WordNet 1.5]
  • 2. to throw from a boat into the water.
  • Syn: deep six, throw overboard. [WordNet 1.5]