adverb/sɑ̃ fot/
without fail, for sure, definitely; Used other than figuratively or idiomatically: see sans, faute; flawlessly, perfectly
“Le travail devra être rendu pour vendredi sans faute.” — The work will have to be done by Friday without fail.
Synonyms: à coup sûr, immanquablement, sans faillir, sans y manquer, parfaitement