An adjective for something that is not as well-known as it should be

Question

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:

unknown
bad
common
contemptible
inconspicuous
ineffective
infamous
inferior
insignificant
little
low
normal
obscure
ordinary
poor
powerless
regular
small
stupid
typical
unimportant
unimpressive
unnoteworthy
unremarkable
usual
weak
unnotable

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?

Answer 1

Underrated might be what you're looking for. It means something that deserves more attention than is given to it.

Answer 2

What about little-known?

little-known (ˌlɪtəlˈnəʊn)
adjective
not widely known; not famed
(Collins)

Little-known is often used to describe something interesting or important but that relatively few people know.

Here are some examples I found online:

• Four little-known funds that deserve a place in your Isa
  (The Telegraph)
• Hear "Money," a Little-Known Piece of Jimmy Page History
  (Guitar World)
• This Little-Known Math Genius Helped America Reach the Stars
  (Smithsonian)
• 16 stunning shots from a little known Instagrammer
  (c|net)

Using the OP, an example would be

The recently proposed problem X has researchers baffled. However, the little-known problem Y might hold the key to solving X.

Answer 3

I would suggest neglected. In context, this carries both connotations of being little known and of this being an unfortunate state of affairs.

As well as Blogg's famous Widget problem, I address the related Gidgit problem presented in A tale of Widgets and Gadgets (Smith, 1937) which has been sadly neglected in the intervening years.

Answer 4

Overlooked or often-overlooked

Overlook

1. Fail to notice

Oxford English Dictionary

As for the phrase often overlooked, we can see this used quite frequently, for instance at the time of writing a Google search for the phrase included

• Single word for "crucial, but often overlooked" - English Language Stack Exchange

• Nine Often-Overlooked Habits That Will Improve Your Financial Health - Forbes

• Often-Overlooked Rules of Grammar - connect - Willow Printing Group

• Tax Hacks 2017: Don’t Miss These 16 Often-Overlooked Tax Breaks - Money Talks News

as four of its top five results. It does seem to be a favorite of those writing clickbait headlines, but the phrase is certainly common.

Answer 5

I think obscure might be a good word for you.

My Mac's thesaurus lists unknown, unnoticed, and forgotten as synonyms for obscure.

The dictionary lists quite a few definitions for it; the one most pertinent for you would be:

obscure (adj.) not famous or acclaimed

_{[Source: WordNet 3.0]}

That meaning would be readily discerned in a sentence like this one:

We will discuss two problems – the first is well-known, while the second is more obscure.

Answer 6

Overshadowed fits nicely here, as the first problem is the cause of the second being unknown.

Problem B, though overshadowed by the more famous Problem A, is nonetheless important in the history of mathematics.

Overshadowed implies that something else has stood out more, and leaves the subject figuratively in the shadow of the other object. It's used in conjunction with that more prominent object, so you will often see it in the form, "A is overshadowed by B". It can be used as an adjective directly modifying the subject, but it should be clear what it being eclipsed by.

Though the superhero had the star role in the film, the overshadowed sidekick was also a superb actor.

Answer 7

unappreciated - maybe doesn't pertain exactly to how little known, more to how little recognized. All are good, except maybe obscure, which doesn't imply that it should be known ( a good thing).

Answer 8

According to what you say "The second problem was published in a book about 70 years ago, but since then, little attention has been given to it." primarily means that the problem was forgotten about, though it may have seemed quite important.

It doesn't say that it should be a well-known problem or that its importance was underestimated. Based on your sentence, a possible word could be "trivialized" or "neglected".

The problem appeared to be unimportant, insignificant at that time; it was a trivial problem, one of little value or importance. Little light was made of this problem. Or it was a neglected problem and little attention was payed to it.

Other possible variants are: ignored, underestimated, underrated, undervalued, understated, underreckoned,treated lightly,depreciated

I personally tend to "underestimated", and "trivialized" or "neglected".

A very good option would be to use two words in a row!

• "The second problem was neglected and underrated (underestimated, undervalued)" which means that there wasn't enough attention payed to it and its importance was underestimated.