资料来源 : WordNet®

nonextant
     adj 1: no longer in existence; lost or especially having died out
            leaving no living representatives; "an extinct species
            of fish"; "an extinct royal family"; "extinct laws and
            customs" [syn: {extinct}] [ant: {extant}]
     2: no longer existing or inaccessible through loss or
        destruction; "its nonextant original was written on
        vellum"- G.B.Saul