limitation vs monkey wrench

limitation

noun
  • An imperfection or shortcoming that limits something's use or value. 

  • The act of limiting or the state of being limited. 

  • A time period after which some legal action may no longer be brought. 

  • A restriction; a boundary, real or metaphorical, caused by some thing or some circumstance. 

monkey wrench

noun
  • An unexpected or troublesome problem, obstacle or dilemma. 

  • A wrench (spanner) with an adjustable jaw. 

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