difficult to decipher
of, relating to, or written with this system of symbols
Undecipherable handwriting or secret symbol.
Any symbol used in this system; a hieroglyph.
A writing system of ancient Egypt, Minoans, Maya and other civilizations, using pictorial symbols to represent individual sounds as a rebus
Not answerable; impossible to answer.
Impossible to dispute or rebut; irrefutable; conclusive.
Something that cannot be answered.