96 Moby Thesaurus words for "deep six": abandon, barrow, beehive tomb, bone house, box grave, burial, burial at sea, burial chamber, burial mound, burying, cast, cast aside, cast away, cast off, castaway, castoff, catacombs, cenotaph, charnel house, chuck, cist, cist grave, cortege, cromlech, crypt, dead march, dice, dirge, discard, discarding, disposal, dispose of, ditch, dokhma, dolmen, dump, dumping, eighty-six, eliminate, elimination, funeral, funeral procession, get quit of, get rid of, get shut of, give away, grave, house of death, jettison, jilt, junk, junking, last home, last post, long home, low green tent, low house, mastaba, mausoleum, monstrance, muffled drum, mummy chamber, narrow house, ossuarium, ossuary, part with, passage grave, pit, pyramid, refuse, reject, rejectamenta, rejection, reliquary, removal, remove, resting place, scrap, scrapping, sepulcher, shaft grave, shrine, slough, stupa, taps, throw away, throw out, throw over, throw overboard, throwaway, tomb, tope, toss overboard, tower of silence, tumulus, vault

Source: Moby Thesaurus II by Grady Ward, 1.0