axiom vs epigram

axiom

noun
  • A seemingly self-evident or necessary truth which is based on assumption; a principle or proposition which cannot actually be proved or disproved. 

  • A fundamental assumption that serves as a basis for deduction of theorems; a postulate (sometimes distinguished from postulates as being universally applicable, whereas postulates are particular to a certain science or context). 

  • An established principle in some artistic practice or science that is universally received. 

epigram

noun
  • A short, witty or pithy poem. 

  • A brief but witty saying. 

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