In Scottish Gaelic it means "my brown-haired daughter" or "my brown-haired girl". In this case it most probably means "my brown-haired girl", since this is the title of a Gaelic love song. By the way in modern Gaelic grammar it should be "mo nighean dhonn", because nighean (girl) is feminine.
It's not really Gaelic.mo duinne is not correct; it should be mo nighean donn, and was later corrected by Diana Gabaldon, who meant to say 'my brown-haired one'.
'Brown' is donn in Scottish Gaelic.
donn
dreathan donn
In Irish it's: Mo ghrá thú a chailín donn / Ta grá agam duit a chailín donn
In Irish (Gaelic): dorchacht or dorchadas.
The Irish word for 'brown' is 'donn' which is pronounced like 'down' in Co. Galway.There are three major dialects in Irish often differing in pronunciation.The (Scottish) Gaelic is also 'donn'. Not sure about pronunciation.
Donn Simione's birth name is Donn Angelo Simione.
Donn Cambern's birth name is Donn Green Cambern.
Donn Clendenon's birth name is Donn Alvin Clendenon.
Donn Arden was born in 1916.
Donn Moomaw is 6' 4".