clue vs datum

clue

noun
  • Information which may lead one to a certain point or conclusion. 

  • An object or a kind of indication which may be used as evidence. 

  • Insight or understanding ("to have a clue [about]" or "to have clue". See have a clue, clue stick) 

verb
  • To provide with a clue. 

  • To provide someone with information which he or she lacks (often used with "in" or "up"). 

datum

noun
  • 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. 

  • A fact known from direct observation. 

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

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