Thank you for your message. However, I think you have misunderstood. Uncountable is a usage note, not a translation. It indicates that the translations are uncountable nouns. You cannot say a nonsense or nonsenses. I'm afraid that unaccountable and unthinkable also don't seem to be appropriate translations for any sense of billvesée that I can find, so I won't be making any changes to the translations here.