ξῡνός (Xynos), κοινός (koinos)

ξῡνός, ή, όν, (ξύν) older form of κοινός, common, public, general, concerningor belonging to all in common, [Ιλιάς]; γαῖα ξυνὴ πάντων earth the commonproperty of all, Ib.; ξ. Ἐνυάλιος, i.e. war hath an even hand, is uncertain, Ib.; ξ. πᾶσι ἀγαθόν [Ηρόδοτος]; ξυνὰ λέγειν to speak for the common good, [Αισχύλος]

Source: Greek-English on-Line Lexicon