There are actually two Hob y Deri Dando-s , a North Wales and a South Wales one. I provided a lot of info to one of the Usenet groups some years ago, which I think Abby Sale copied to Mudcat (I wasn't a member at the time).

The phrase that's boggling you is Siani Fach Fwyn. (Shannee Vach Vooeen - with the ch as in the German, ie. Bach) and means Gentle Little Sian (note: female), Sian being Jane in Welsh.

Maybe someone can dredge up the old thread ... ? The Druid thing (ie. *real* druids is, umm, tenuous) But the druids did worship the Oak. Pigs used to be grazed in oak groves to feed on the acorns.

Sian not under the oaks ...