κοινοπάτωρ
From LSJ
ὁμοῦ ἦν καὶ ἔχειν τὴν πόλιν καὶ τὸ γένος ὅλον μετὰ τῆς πόλεως → it was much the same thing to have the city and to have the whole race together with the city
Greek Monolingual
κοινοπάτωρ, -ορος, ὁ, ἡ (Α)
αυτός που έχει τον ίδιο πατέρα με κάποιον άλλο, ομοπάτριος.
[ΕΤΥΜΟΛ. < κοινός + -πάτωρ (< πατήρ), πρβλ. φιλο-πάτωρ, ψευδο-πάτωρ.