enigma vs puzzle

enigma

noun
  • A riddle, or a difficult problem. 

  • A species of grasshopper, Oedaleonotus enigma. 

  • Mysteriousness; obscurity; lack of clarity. 

  • The Talaud kingfisher, Todiramphus enigma. 

  • A rare species of moth, Heliothis enigma. 

  • A style of literature characterized by obscurity and hints of transcendental meaning. 

  • Something or someone puzzling, mysterious or inexplicable. 

  • A protein with three LIM domains (a conserved cysteine- and histidine-rich structure of two adjacent zinc fingers) at the C terminus that regulates protein phosphorylation. 

  • Riddles and puzzles, collectively. 

puzzle

noun
  • A riddle. 

  • Anything that is difficult to understand or make sense of. 

  • The state of being puzzled; perplexity. 

  • A game for one or more people that is more or less difficult to work out or complete. 

  • A jigsaw puzzle. 

  • A crossword puzzle. 

verb
  • To think long and carefully, in bewilderment. 

  • To perplex, confuse, or mystify; to cause (someone) to be faced with a mystery, without answers or an explanation. 

  • To make intricate; to entangle. 

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