Hi
Lissa,
I found this in the book "Celtic baby names" by
Judy Sierra:
Names from the Isle of Man:
Donal m. (DAWN-uhl) From the Old Irish Name Domnall: 'domun'='world' + 'gal'='ardor, valor'. Several Manx chieftains and saints have borne this name. Nicknames: Dolen, Dolyn (DAW-luhn).
Regards,
Satu