Source : WordNet®

bye-bye
     n : a farewell remark; "they said their good-byes" [syn: {adieu},
          {adios}, {arrivederci}, {auf wiedersehen}, {au revoir},
         {bye}, {cheerio}, {good-by}, {goodby}, {good-bye}, {goodbye},
          {good day}, {sayonara}, {so long}]