2.nosity can also be used to generalise about something (e.g. a person's situation) much in the same way as words like "malarkey" or "fiasco" are.
3.also similar to nub ( as in, the nub and gist), nosity can mean the point.
2."yeh, remember lily and her nosity about shoes?"
3."the general nosity was that she was a smelly poo"