Cadmeun or Cadmean: How To spell?

The word Cadmeun is misspelled against Cadmean, an adjective meaning "pertaining to Cadmus, a fabulous prince Thebes, who was said to have introduced into Greece the sixteen simple letters the alphabet -- /, /, /, /, /, /, /, /, /, /, /, /, /, /, /, /. These are called Cadmean letters."