This song must be pretty ancient as Soodlum's 100 Irish Ballads Volume 1
, where I first came across the song, claims that it is in the Joyce Collection, the lyrics and music being written around 1852.
It's a sad little song of unrequited love and separation. The version in Soodlums has just three verses and appears to be incomplete. It is a real mood song, one is left in the air as to how things will turn out.