ἀχέτας
From LSJ
ἐπ' αὐτὸν ἥκεις τὸν βατῆρα τῆς θύρας → you've come to the crux of the matter, come to the point, hit the nail on the head, you've come to the very threshold of the door, you are come to the very threshold of the door, you've arrived at the truth of the matter
English (LSJ)
or ἀχέτᾰ, Dor. and Att. for ἠχέτης (q. v.).
German (Pape)
[Seite 417] ὁ, dor. für ἠχέτης, tönend, κύκνος Eur. El. 151; Φοῖβος Dionys. ep. 2; τέττιξ Archi. 29 (VII, 213); geradezu für die Cicade gesagt, Arist. H. A. 4, 7; Ar. Av. 1095 Pax 1159.
Greek (Liddell-Scott)
ἀχέτας: ἢ ἀχέτᾰ, Δωρ. καὶ Ἀττ. ἀντὶ ἠχέτης, ὃ ἴδε.