extant

defunct, destroyed, exterminated, kaput (also kaputt)

departed, gone, lost

nonexistent

idle, inactive, inert

coming, future, unborn

completed, concluded, done, ended, finished, over, terminated, through, up

ancient, antediluvian, antiquated, antique, archaic, dated, fusty, musty, obsolete, old, oldfangled, old-fashioned, old-time, out-of-date, outworn, passé

bygone, erstwhile, former, past