head-scratching vs labyrinthal

head-scratching

adj

  • Confusing, perplexing, puzzling. 

noun

  • Confusion. 

labyrinthal

adj

  • Like a maze or labyrinth, intricate or convoluted. labyrinthine. 

How often have the words head-scratching and labyrinthal occurred in a corpus of books? (source: Google Ngram Viewer )