datum vs postulate

datum

noun
  • A fact known from direct observation. 

  • A premise from which conclusions are drawn. 

  • A floating reference point, or SLDMB, used to evaluate surface currents in a body of water. Often employed by coastal search and rescue. 

  • A fixed reference point or set of reference points which precisely define a system of measurement or a coordinate system. 

verb
  • To provide missing data points by using a mathematical model to extrapolate values that are outside the range of a measuring device. 

postulate

noun
  • A fundamental element; a basic principle. 

  • An axiom. 

  • Something assumed without proof as being self-evident or generally accepted, especially when used as a basis for an argument. Sometimes distinguished from axioms as being relevant to a particular science or context, rather than universally true, and following from other axioms rather than being an absolute assumption. 

  • A requirement; a prerequisite. 

adj
  • Postulated. 

verb
  • To appoint or request one's appointment to an ecclesiastical office. 

  • To assume as a truthful or accurate premise or axiom, especially as a basis of an argument. 

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