It's a trad song, maybe performed most recently by Clannad. I am sure that 'siuil' means literally 'walk' and I know that 'a rún' means 'my love'.

See the song below, with the Irish chrus translated.

"Background
The verses of this song refer to a lover's enlistment in the Irish Brigade who left Ireland after the Williamite War (1691) to serve in the French Army. In Ireland these gallant soldiers were referred to as 'WIld Geese.'

Lyrics
Provided by Lindsay Labanca

I wish I was on yonder hill
'Tis there I'd sit and cry my fill,
And every tear would turn a mill,
Iss guh day thoo avorneen slawn.

Chorus (in phonetic Gaelic)
Shule, shule, shule aroon,
Shule go succir agus, shule go kewn,
Shule go dheen durrus oggus aylig lume,
Iss guh day thoo avorneen slawn.

I'll sell my rock, I'll sell my reel,
I'll sell my only spinning wheel,
To buy my love a sword of steel
Iss guh day thoo avorneen slawn.

Chorus

I'll dye my petticoats, I'll dye them red,
And 'round the world I'll beg my bread,
Until my parents shall wish me dead,
Iss guh day thoo avorneen slawn.

Chorus

I wish, I wish, I wish in vain,
I wish I had my heart again,
And vainly think I'd not complain,
Iss guh day thoo avorneen slawn.

Chorus

But now my love has gone to France,
To try his fortune to advance;
If he e'er come back, 'tis but a chance,
Iss guh day thoo avorneen slawn.

Chorus


Translation
Provided by Lindsay Labanca
Chorus:
Come, come, come, O love,
Quickly come to me, softly move;
Come to the door, and away we'll flee,
And safe for aye may my darling be!"

http://www.google.com/search?q=cache:www.jtwinc.com/clannad/...