hieroglyph

An element (individual sign or glyph) of a hieroglyphic writing system.

Hieroglyphs were discovered on the wall inside the temple.

Mayan Hieroglyphs as Linguistic Evidence. In Third Palenque Round Table, 1978, vol. V, part 2, edited by Merle Greene Robertson, pp. 204-216.

An element (individual sign or glyph) of a hieroglyphic writing system.

Any obscure or baffling symbol.

With your handwriting, it's no surprise the Prof can't read your hieroglyphs!

"There are SCPs with antimemetic properties," Marion goes on. "There are ideas which cannot be spread. There are entities and phenomena which harvest and consume information, particularly information about themselves. You take a Polaroid photo of one, it'll never develop. You write a description down with a pen on paper and hand it to someone— but what you've written turns out to be hieroglyphs, and nobody can understand them, not even you. You can look directly at one and it won't even be invisible, but you'll still perceive nothing there."

To represent by hieroglyphs.