involutional vs labyrinthine

involutional

adj
  • of or pertaining to involution 

  • characterized by involution 

labyrinthine

adj
  • Convoluted, baffling, confusing, perplexing. 

  • Physically resembling a labyrinth; with the qualities of a maze. 

  • Relating to the labyrinth of the inner ear. 

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