datum vs declaration

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. 

declaration

noun
  • A written or oral indication of a fact, opinion, intention, belief, etc. 

  • In common law, the formal document specifying plaintiff's cause of action, including the facts necessary to sustain a proper cause of action, and to advise the defendant of the grounds upon which he is being sued. 

  • The specification of an object, such as a variable or function, establishing its existence but not necessarily describing its contents. 

  • The act, by the captain of a batting side, of declaring an innings closed. 

  • The act or process of declaring. 

  • A list of items for various legal purposes, e.g. customs declaration. 

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