In french idioms rien does not have a correct translation (should be nothing)
Are you asking about the hints you get when you pass the mouse over the word "rien" in the sentence? There's only one list of hints for each word, not a separate list for each sentence. So in idioms the list is pretty much never going to be correct. But you can't translate idioms word for word in any case.
I understand this but usually nouns and adjectives have a definition. I got that as my first question and had to Google what it meant as the hint when i hovered over it had nothing in it but rien.