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
difficult to decipher
of, relating to, or written with this system of symbols
A character or symbol (usually nonalphanumeric) that represents a word or phrase.
A kind of word puzzle: a logogriph.