conjecture vs presumption

conjecture

noun
  • A statement likely to be true based on available evidence, but which has not been formally proven. 

  • A statement or an idea which is unproven, but is thought to be true; a guess. 

  • A supposition based upon incomplete evidence; a hypothesis. 

verb
  • To infer on slight evidence; to guess at. 

  • To guess; to venture an unproven idea. 

presumption

noun
  • the belief of something based upon reasonable evidence, or upon something known to be true 

  • the condition upon which something is presumed 

  • the act of presuming, or something presumed 

  • An inference that a trier of fact is either permitted or required to draw under certain factual circumstances (as prescribed by statute or case law) unless the party against whom the inference is drawn is able to rebut it with admissible, competent evidence. 

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