From Old Italian *sbagliare*, derived from the prefix *s-* (indicating undoing or reversal) + *bagliore* (a flash, glare), evolving to mean "to go wrong" or "to miss the mark." Cognate with the concept of straying from the right path.

Italians use *sbagliare* very naturally and frequently — *sbagliare strada* (wrong road), *sbagliare numero* (wrong number), *sbagliare persona* (wrong person). The reflexive form *sbagliarsi* is equally common and means "to be mistaken" (e.g. *mi sono sbagliato* — "I was wrong"). Don't confuse it with *fare un errore*, which is more formal and bookish.