remains to be seenUsed to introduce something that is still unknown or needs to be determined. In ordinary use, it is usually conjugated, as in « il reste à savoir »; the example below mentions the exact infinitive form.
FR: L’expression « rester à savoir » s’emploie pour évoquer une question qui demeure sans réponse.
EN: The expression “rester à savoir” is used to refer to a question that remains unanswered.