I’m rereading Diana Gabaldon’s Outlander series, and in the first couple of books, Jamie calls Claire mo duinne, which means, “my brown one.”
However, later in the series, he calls her mo nighean donn. Gabaldon explains the disprepancy here (11th question down), but I was hoping for a more accurate translation.
Without looking at your link, I can tell you that the explanation is that Gabaldon got corrected a few dozen times by people who can actually speak Gaelic; “mo duinne” is gibberish, “duinne” being a comparative adjective, not a noun.
To answer your question, though: “mo nighean donn” literally translates to “my brown girl” or “my brown daughter”.
Well, to her credit, Gabaldon does admit the boo-boo, and says she corrected it for future books.