This is probably a stupid question, but it bothers me so I’m posting this…
Sappho fr. 17 line 9 reads (Sappho is addressing Hera):
πρὶν σὲ καὶ Δί’ ἀντίαον κάλεσσαι
My Loeb translates “until they called on you and Zeus the god of suppliants”.
I guess “god of suppliants” comes from ἀντίαον. I can’t find ἀντίαος in LSJ or Perseus’ Word Study tool. Is it some form of ἀντιάω?
Yes. It must be a masc. acc. sg. participle of ἀντιάω, taken as a substantive and referring to Δία.
(I think she refers to him, the subject of her poem, on the same level of the god Zeus,
and so the participle is sg. and not pl. Perhaps it was also subject to meter constraints.)
That’s what I was suspecting too. So is it a particularity of Aeolic that the forms aren’t nom. ἀντιάων and acc. ἀντιάοντα? Where could I read more about this? (I’ve read Annis’ great introduction to Lesbian Aeolic, but I couldn’t find the answer there.)
I apologize. You’re absolutely right that if it’s from ἀντιάω, it should be ἀντιάοντα.
(I’m not sure whether the accusative participle had this ending in Lesbian Aeolic.)
The placement of the accent, and the ending, suggests it’s something different.
It’s interesting that in the TLG database, this fragment doesn’t have this verb. Maybe
it was edited in the Loeb edition from another manuscript.
All I have is this incomplete line:
πρὶν σὲ καὶ Δί’ ἀντ[
I did find this line in fragment 129 of Alcaeus, which is perhaps the source of this addition:
κἀπωνύμασσαν ἀντίαον Δία
σὲ δ’ Αἰολήιαν [κ]υδαλίμαν θέον
πάντων γενέθλαν, τὸν δὲ τέρτον
?τόνδε κεμήλιον ὠνύμασς[α]ν
Ζόννυσσον ὠμήσταν.
The line is actually incomplete in the Loeb as well, but it has been finished by the editor:
πρὶν σὲ καὶ Δί’ ἀντ[ίαον κάλεσσαι
I didn’t mention this to make things simpler. But the example you found shows that it exists outside the imagination of the editors 
. The problem persists, what is this word…?
I guess ἀντίαος is an adjective meaning “accepting suppliants”.
Could very well be the intended meaning of this adjective.
I’m sorry for writing this nonsense. The subject of the poem is Hera, as you said,
and not some male him. And as I read the various translations, it seems this adjective
modifies only Zeus, as to be expected.