Acheloius
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
Latin > English (Lewis & Short)
Ăchĕlōĭus: a, um, adj. id..
I Pertaining to the river Achelous, Verg. G. 1, 9; Ov. H. 16, 265: Callirrhoë, daughter of Achelous, id. M. 9, 413.—
II Aetolian: heros, i. e. Tydeus, the son of Oeneus, king of Aetolia, Stat. Th. 2, 142.
Latin > French (Gaffiot 2016)
Ăchĕlōĭus,¹⁵ a, um, d’Achéloüs || heros Stat. Th. 2, 142, le héros étolien [Tydée] || pocula Acheloia Virg. G. 1, 9, coupes d’eau.