peril vs pitfall

peril

noun
  • Something that causes, contains, or presents danger. 

  • A situation of serious and immediate danger. 

  • An event which causes a loss, or the risk of a specific such event. 

verb
  • To cause to be in danger; to imperil; to risk. 

pitfall

noun
  • A potential, unsuspected, hidden problem, hazard, or danger that is easily encountered but not immediately obvious. 

  • A type of trap consisting of a concealed pit in the ground, which the victim is supposed to fall into and not be able to get out from. 

  • An antipattern. 

  • Subsidence below ground in a mine, which can cause the ground level above to drop. 

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