OK. I used cryptic as a noun even though I knew I couldn't. But I checked anyway--hoping against hope that perhaps it had transmuted to the point that we could have a 'cryptic.' And we still can't, though I can--tra la!

Anyway, cryptogram would have been just as incorrect in the sense I was using the non-existent 'cryptic' as a noun.

But what would be the word? Let's say you pepper your language with words that really aren't words--just occasional seasonings--nonce words--but not nice nonce words meant to be clever, but, instead, created words with only an insider's knowledge. Like cool row for clown. That wouldn't really be a nonce word because its meaning couldn't be understood unless you'd been following an eccentric line of thought.

Certainly James Joyce pulls such tricky words out of his enormously cocked hat--but what do we call those words? I like cryptics, but would like to know whether there is a bona fide word already out there.