DEOÍNDÍ

Deoíndí ó deighil dum, is tá mo ghrá chomh deas;
Deoíndí ó deighil dum, 's nach bhféadaim éirí as -
Is Deoíndí ó deighil dum!

Deoíndí ó deighil dum, is tá mo chroí chomh trom;
Deoíndí ó deighil dum, le cioch a chaithfi i dtom-
Is Deoíndí ó deighil dum!

Deoíndí ó deighil dum, nach iomaí cor is cleas;
Deoíndí ó deighil dum, do chroí nach bhuair mé 'mach -
Is Deoíndí ó deighil dum!

Those are the words as given by Míchéal Ó éidhin in his songbook "Cas Amhrán", but you are liable to hear people making up other words to fit between the refrain lines
My copy of "Cas Amhrán" is the first edition published by Cló Chois Fharraige, 1975, but the book is still available from Cló Iar-Chonachta