prealphabet

From pre- +‎ alphabet.

prealphabet (plural prealphabets)

1. A writing system that was used before an alphabet, or later developed into an alphabet.
   • 2018, Bob Yareham, English Actually:

     Our own dearly beloved Anglo Saxons used a very basic prealphabet consisting of 'runes' (straight lines scratched onto wood, bone or stone) called, rather quaintly I think, 'futhorc.'