LATIN DICTIONARYLexicon Latīnum
proper noun · masculinesecond declension

Achelōus

Achelōus m sg (genitive Achelōī)
Classical[a.kʰɛˈɫoː.ʊs]Ecclesiastical[a.keˈlɔː.us]

Meaning

  1. a river in Greece, forming the boundary between Acarnania and Aetolia.
  2. Achelous, a Greek river god
    Adnuit Aegides, “utar” que “Acheloe, domoque / consilioque tuo” respondit; et usus utroque est.Theseus approved, and responded "I will use, Achelous, [your] home and [your] advice"; and [there] is a use of both.8 CE, Ovidius, Metamorphoses 8.560

Declension

declension
formsingularplural
nominativeAchelōus—
genitiveAchelōī—
dativeAchelōō—
accusativeAchelōum—
ablativeAchelōō—
vocativeAchelōe—

Ăchĕlōŭs, i, m., Ἀχελῶος.
I. A celebrated river of Middle Greece, which, rising in Pindus, separates Aetolia from Acarnania, and empties into the Ionian Sea, now the Aspropotamo, Mel. 2, 3, 10; Plin. 4, 1, 2 al.—Hence,
II. The river-god Achelous, Ov. M. 8, 549 sq.; 10, 8 sq.; Prop. 2, 34, 33 al.

Origins

Borrowed from Ancient Greek Ἀχελῷος (Akhelōîos).

In the Academy Smith's classical dictionaries

Quick answers

What does Achelōus mean in Latin?
Achelōus, a proper noun, means “a river in Greece, forming the boundary between Acarnania and Aetolia.; Achelous, a Greek river god”.
What is the genitive of Achelōus?
The genitive singular is Achelōī. Achelōus is masculine, second declension.
How do you pronounce Achelōus?
In classical Latin, [a.kʰɛˈɫoː.ʊs]; in ecclesiastical (church) Latin, [a.keˈlɔː.us].