neo-Sinaitic alphabet, writing system used in many short rock inscriptions in the Sinai Peninsula, not to be confused with the Sinaitic inscriptions, which are of much earlier date and not directly related. Neo-Sinaitic evolved out of the Nabataean alphabet in the 1st century ad and was in use perhaps until the 4th century ad; inscriptions date primarily from the 2nd and 3rd centuries. The chief importance of the neo-Sinaitic alphabet is as the probable link between the Nabataean alphabet and the Arabic.