complication vs explanation

complication

noun
  • The act or process of complicating. 

  • A person who doesn't fit in with the main scheme of things; an interloper. 

  • The state of being complicated; intricate or confused relation of parts; complexity. 

  • A feature beyond basic time display in a timepiece. 

  • A disease or diseases, or adventitious circumstances or conditions, coexistent with and modifying a primary disease, but not necessarily connected with it. 

explanation

noun
  • The act or process of explaining. 

  • Something that explains, makes understandable. 

  • A resolution of disputed points pursuant to discussion; a mutual clarification of disputed points; reconciliation. 

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