I need a translation of the following line which is also
the title of the song.

AR EIRINN NI NEOSFAINN CE HI

also:
cailin ban

thanks!!

I would not, even if I were to gain Ireland, reveal her name

Cailín bán - white girl

I did notice at the end of the song they do not repeat
the phrase in question, instead they say "But for Ireland
I won't tell her name". I don't know if this implies a
direct translation of the previous verse.

Thanks for the Translation!!!