Hieroglyphic
/ˌhaɪɹəˈɡlɪfɪk/
noun
(chiefly in the plural) a writing system of ancient Egypt, Minoans, Maya and other civilizations, using pictorial symbols to represent individual sounds as a rebus
Any symbol used in this system; a hieroglyph
(by extension) undecipherable handwriting or secret symbol
adjective
Of, relating to, or written with this system of symbols
“hieroglyphic obelisk”
Difficult to decipher