Go raibh maith agat!

Óró is sé do bheatha abhaile, and Óró a Shadhbh, a Shadhbh Ní Bhruinnealla

In both cases according to https://www.teanglann.ie/en/fgb/or%c3%b3 it will mean oho in English which means an interjection for the following:

oho
interjection
(used as an exclamation to express surprise, taunting, exultation, etc.)


so maybe its a feeling of jubilation, excitement, elation being expressed that Gráinne Mhaol - the Irish Pirate Queen is coming over the seas back to Ireland (Tá Gráinne Mhaol ag teacht thar sáile); and the Máistir báid mhóir who has fallen in love with Sadhbh says it when he sees her when sailing his boat (Galway Hooker) to the village of Inis Ge (Baile Inis Gé) !!!

I know a bit obscure - but Ive wondered this also. I doubt its used in the modern language and only features in poems and old sean-nós songs etc.

Variant Oró.

grma