Looking for a word for: "not easily recognizable"

Question

I am looking for a word.

The word should mean something that is:

"not easily recognizable"

E.g.

'His hat was not >>easily recognizable<<'

'The problem was not >>easily recognizable<<'

Answer 1

Inconspicuous

adj. not easily noticed or seen; not prominent or striking

Answer 2

For one of your cases, you could use 'obscure'

The problem was obscure

Obscure (MW, noun definitions 1c and 2)

not clearly seen or easily distinguished

not readily understood or clearly expressed

But this doesn't apply as well to the hat. As expressed in comments above, what part of 'not recognizable' applies? Is the hat not recognizable as a hat? Is the hat hidden by something else?

Answer 3

If you are looking for a word that means "has not been encountered before", the best word would be "unfamiliar". This would fit with your second example: "The problem was unfamiliar" would mean "I have not seen this problem before, so I do not know the answer to it".

For the hat example, this would mean "I have not seen his hat before", but it's not clear you want that meaning.

Answer 4

The hat was uncommon; it was an uncommon hat.

However, I would say it like this: The style of hat was uncommon.

For clothing and hats, styles can be said to be common or uncommon in terms of being easily recognizable.

Answer 5

The closest thing that I can think of would be unidentifiable:

If something or someone is unidentifiable, you are not able to say exactly what it is or who they are.

Your examples:

His hat was unidentifiable.

The problem was unidentifiable.

Answer 6

How about peculiar? It's always used to refer to something/someone/anything really that does not fit into the speaker's previous experience.