puzzle vs uncertainty

puzzle

noun
  • The state of being puzzled; perplexity. 

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

  • A riddle. 

  • 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. 

uncertainty

noun
  • Something uncertain or ambiguous. 

  • Doubt; the condition of being uncertain or without conviction. 

  • A parameter that measures the dispersion of a range of measured values. 

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