Zacynthius
Could not find Zacynthiust in Logeion dictionaries.
Zacynthiust Proper-name adjective: masculine nominative singular of Zacynthius
Zăcynthĭus, a, um, v. Zacynthus.
Zăcynthĭus, (16) a, um (Ζακύνθιος), de Zacynthe : Pl. Merc. 904 ; Plin. 35, 178.