apsinthion

> Apsinthos, Apsynthos (Dion., Steph. Byz.) - a frontier river and a
> main settlement of the tribe of Apsinthioi (Hdt.) to the north of

the

> Thracian Chersones (modern Galipoli peninsula); Apsinthis

(Apsynthis)

> (Strab., Steph. Byz.) - the country of the same tribe. The name is
> linked with apsinthion `wormwood', a word thought to be of Pelasgian
> origin in the Greek language, or with the Illyrian river name Apsus,
> derived from the IE *a^p- respectively *ab- `water, river'.

Partridge, in Origins, derives apsinthion from Old Persian, but cites
no etymon. What Old Persian word could he have been thinking of?
What was his source, I wonder? I could see ap- 'water' in there, but
would like to know what Persian connection has been postulated for
this word, if any.