hieroglyphic vs hieroglyphical

hieroglyphic

adj
  • of, relating to, or written with this system of symbols 

  • difficult to decipher 

noun
  • 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 

hieroglyphical

adj
  • Related to or resembling hieroglyphs; hieroglyphic. 

How often have the words hieroglyphic and hieroglyphical occurred in a corpus of books? (source: Google Ngram Viewer )