It's context dependent. "nearly" means "not quite reaching the target", so if you are talking about "doubling" something, then "nearly doubling" it would mean t

It's context dependent. "nearly" means "not quite reaching the target", so if you are talking about "doubling" something, then "nearly doubling" it would mean to end up with slightly less than double. That said, I believe it is usually used to mean "less than". In this case, I would use "just over" instead, ie, "closed, it's just over double that".