Droimdfhionn is an older spelling of Druimín. The song is also known as An Druimeann Donn Dilis.
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Here are the lyrics given in the Joe Heaney/ Seosamh Éiniú/Ó hÉanaí archives, where you will also find a sound recording https://www.joeheaney.org/en/druimin-donn-dilis/:

DRUIMÍN DONN DÍLIS

‘A dhruimín donn dílis, a shíoda na mbó
Cá ngabhann tú san oíche, nó cá mbíonn tú sa ló?’
‘Ó, bímse ar na coillte, mo bhuachaill ‘mo chóir
Agus d’fhág sé siúd mise ag sileadh na ndeor.’

‘Níl fearainn, níl tíos agam, níl síoda ná sról
Níl fear le mo thaobh-sa, níl fíonta ná ceol
Ach ag síor-ól an uisce go minic sa ló
Agus beathuisce is fíonta ag mo naimhde ar bórd.’

Dhá bhfaighinnse cead aighnis nó radharc ar an gcoróin
Sasanaigh do leidhbfinn mar a leidhbfinn seana-bhróg
Thrí chnoic is thrí ghleannta, is gleannta dubha ceo
Agus siúd mar an bhréagfainn mo dhruimin donn óg.

TRANSLATION

‘Oh faithful brown white-backed one, finest of cows,
where do you go at night? Where do you spend the day?’
‘Oh, I am in the forest, with my herd in attendance;
and this has left me shedding tears.’

I have neither lands nor household, neither silk nor satin;
there’s nobody with me, neither wine nor music,
but constantly drinking water many times daily –
while whiskey and fine wines abound on the table of my enemies.

If I had leave to complain, or a glimpse of the crown,
I would batter the English just as I’d kick an old shoe
through hills and dark, foggy glens –
and that’s how I’d win my young brown white-backed cow!

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here is a modern rendition by Lorcan Mac Mathúna https://soundcloud.com/evolutionofsound/an-droimeann-donn-dilis
Lorcan's recording is also on Bandcamp and on Youtube.

https://www.youtube.com/watch?v=UvM_c1egNWI - singer Niamh Parsons

https://www.youtube.com/watch?v=7fz2Kr4sRR4 probably Peg Clancy Power