paramour
From LSJ
English > Greek (Woodhouse)
substantive
Ar. and P. μοῖχος, ὁ, V. κοινόλεκτρος, ὁ, ἀνὴρ ἔπακτος, ἀνὴρ θυραῖος.
a wife is wont to imitate her lord and take a paramour: V. μιμεῖσθαι θέλει γυνὴ τὸν ἄνδρα, χἄτερον κτᾶσθαι φίλον (Euripides, Electra 1037).