WordWeb Online

1. Toss out; get rid of
   "deep-six these old souvenirs!"
   - give it the deep six
    
2. Throw from a boat
   - throw overboard

Derived forms: deep-sixing, deep-sixes, deep-sixed

Type of: cast aside, cast away, cast out, chuck out, discard, dispose, fling, put away, throw, throw away, throw out, toss, toss away, toss out