I read this sentence in another post:
But we will assign another meaning to the kanji 貝.
Putting aside any other problems with this sentence, I feel that もう一つ isn't the right word to use for 'another' in this context. I may of course be wrong, but I would have gone with 別の or 他の instead, but I can't explain why (maybe because I'm talking nonsense).
Anyway, I'm now wondering what the difference is between もうひとつ, 別 and 他 when used to mean 'another'.