There are two related problems that I am working on. The first problem is very famous. The second problem was published in a book about 70 years ago, but since then, little attention has been given to it. What adjective can I use to describe the second problem?
I looked for antonyms of "famous" and got a long list of adjectives:
But, most of them imply that the second problem is not very important or interesting. I do not want to imply this; on the contrary, I want to imply that it is important and interesting, only it has not been given sufficient attention. What adjective can I use?