The Oxford Thesaurus An A-Z Dictionary of Synonyms - extinct adj.

1) defunct, dead, died out, gone, departed, vanished: These are the bones of an extinct species of flying mammal. 2) dated, outmoded, old-fashioned, antiquated, obsolete, archaic, out of date, antediluvian, ancient, old hat, pass‚, d‚mod‚: High-button shoes and bustles have been extinct for almost a century. 3) out, extinguished, quenched, burnt- or put or snuffed out; inactive, dormant: The lake is in the caldera of an extinct volcano.