Hieroglyphical and Indecipherable

Hieroglyphical adjective - Written in or belonging to a writing system using pictorial symbols.

Indecipherable and hieroglyphical are semantically related. In some cases you can use "Indecipherable" instead an adjective "Hieroglyphical".

Indecipherable adjective - Incapable of being read or deciphered.

Hieroglyphical and indecipherable are semantically related. You can use "Hieroglyphical" instead an adjective "Indecipherable".