hieroglyphic vs unclear

hieroglyphic

adj
  • difficult to decipher 

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

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 

unclear

adj
  • Not clearly or explicitly defined. 

  • Not easy to see or read; indecipherable or unreadable. 

  • Ambiguous; liable to more than one interpretation. 

  • Not having a clear idea; uncertain. 

verb
  • To undo the process of clearing. 

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