Ζῆν οὐκ ἄξιος, ὅτῳ μηδὲ εἷς ἐστι χρηστὸς φίλος → Life is not worth living if you do not have at least one friend.
συνέπαινος, ὁμόλογος, συγγνώμων, σύμψηφος