Neither word has any particular association with D&D for me. The only thing I think of when hearing the word "Deva" is the aforementioned Bazaar of Deva from the Myth Adventures books.
Aasimar was one of those silly made-up words that they stuck throughout 2E in order to avoid the devil-worshiping accusations that were prevalent at the time among a few outspoken members of the general public, and strip all real-world religion out of D&D. I never played 2E, so never encountered aasimar or tenaari (or whatever it was that they called the demons or devils). In AD&D we just called them angels, demons, or devils. No history there.
Then we played 3.0/3.5 for many years, but it was always the same campaign. Our group never changed out characters, and so didn't incorporate races or classes from the new books. We had the core set and the psionics book, and that was it. The psionic races were ignored (we had our own house-ruled race that used psionics). I mention this because in my opinion it was after the introduction of the book that let you play monster races that the aasimar and tieflings came into the forefront. People could, and did, play them as characters now. That increased their interest and visibility, and hence the general awareness of those racial names. It never happened in our group. I bet most of our players would have no idea what an aasimar was if I asked them.
So despite playing D&D for many years since aasimar were introduced, it has practically zero meaning to me. I like deva better than aasimar as a name, but I think it might have been better yet to just call them celestials. As for nephilium, wasn't that a strange transparent metal in D&D? I had a sword made out of it - but it could just be the DM making stuff up. He does that a lot.
