Sharing this here because the ask wouldn't send. It's from @justwriterbritt
It occurred to me a few weeks back, when an author said Jaime in French is "I love," that Brienne sounds like "brillant," in a French accent. No, I don't think the main author (G-whatev-M) was trying to imply how intelligent she is, but that she's shiny and cuts deep, like a sword or a rare, blue diamond, and obviously, she has admirable qualities.
See: https://www.etymonline.com/word/brilliant#etymonline_v_17121
This makes me wonder if Gal of Morne's legendary sword might be a huge diamond.
When it comes to the Jaime=J'aime thing, I am never sure if that is deliberate or pure coincidence. Having attempted to write some original fiction myself, I know my first instinct isn't to go and look up etymologies when naming characters, but just pick what I think sounds good. Sure, sometimes etymologies may sway me on picking certain names, but the name that just "works" for characters is going to be more important than their meaning.
Now, I'm not a professional author like GRRM is, and he might have a totally different approach to me, but I doubt that George went looking through etymologies when naming each and every one of his characters. He seems to pick the names for his characters from tons of different places and often the etymology has no link to the themes of the character. For example, Jon Snow is a main character so if GRRM put much stock in etymology, his name would mean something important. However, Jon is just a shortened form of the Hebrew John which means "God is Gracious", an idea which doesn't seem to have any link to Jon's arc or the themes in his story. I think George probably picked Jon not because of its etymological roots, but because it is a simple, non-flashy name that would be given to a Joe Bloggs type character. It is perfect for hiding an illustrious family legacy.
Now, to Jaime. Jaime's name is certainly interesting as it seems to break the Ty- prefix trend that is common in the rest of House Lannister (which was probably originally done to create a subtle link between Tyrion and Tywin in the readers' minds, as their connection is important thematically). As Jaime (and Cersei's) names break this trend, GRRM probably got them from another source than Tyrion/Tywin/Tytos/Tyland, and maybe even looked to etymology. However, do we know that "J'aime" is the etymology he would have found? If you look up the name "Jaime" on any baby name website, it tells you it is the Spanish/Portuguese version of the English name "James". Both Jaime and James ultimately come from the Latin "Jacobus", which is itself a translation of the Hebrew name "Jacob" which means "supplanter" or "heel". That etymology seems mighty relevant given the "Jaime was born clinging onto Cersei's heel" story in ASOIAF is a twist on the Jacob/Esau story from the Bible, in which Jacob clung to Esau's heel as they were born and later stole Esau's inheritance. Therefore if GRRM did use etymology in picking Jaime's name, I think it is likely this biblical reference was more influential than the French "J'aime" in swaying GRRM's choice, but I'm not 100% on that,
Now onto Brienne. If there is one thing we know about the pronunciation of names in ASOIAF, it is that GRRM can't seem to stay in his lane. In the audio books narrated by Roy Dotrice (which presumably had some input from GRRM, as they were friends), her name is pronounced "Bry-een" which is obviously very different from "brillant". GRRM is also famous for pronouncing names differently from interview to interview and I think has on occasion said you can pronounce them however you want. I therefore don't think GRRM would be swayed to name a character by pronunciation rules in a language he doesn't speak (and the same goes for J'aime) and would not use this specific pronunciation to hide a key plot clue.
Finally, I very much doubt we are going to see Galladon of Morne's legendary sword and ever get to determine what it is made of. The sword that is important to Brienne's arc is Oathkeeper, and although the legend of Galladon of Morne's embues Oathkeeper with extra meaning, it is Oathkeeper that will be important later on. We also know both who made Oathkeeper and what it is made of, so there is no new information that can be revealed about its qualities. The only sword that GRRM has hinted at having important special qualities that will be revealed later is Dawn (which seems to be made of some type of space rock) and Dawn's importance is possibly linked with whatever was going on with Ashara Dayne.
