cardinal vs principal

cardinal

adj
  • Of fundamental importance; crucial, pivotal. 

  • Having a bright red color (from the color of a Catholic cardinal's cassock). 

  • Of or relating to the cardinal directions (north, south, east and west). 

  • Describing a "natural" number used to indicate quantity (e.g., zero, one, two, three), as opposed to an ordinal number indicating relative position. 

noun
  • One of the officials appointed by the pope in the Roman Catholic Church, ranking only below the pope and the patriarchs, constituting the special college which elects the pope. (See Wikipedia article on Catholic cardinals.) 

  • Any of various related passerine birds of the family Cardinalidae (See Wikipedia article on cardinals) and other similar birds that were once considered to be related. 

  • A deep red color, somewhat less vivid than scarlet, the traditional colour of a Catholic cardinal's cassock. (same as cardinal red) 

  • A woman's short cloak with a hood, originally made of scarlet cloth. 

  • Any of a genus of songbirds of the finch family, Cardinalis. 

principal

adj
  • Primary; most important; first level in importance. 

  • Chosen or assumed among a branch of possible values of a multi-valued function so that the function is single-valued. 

noun
  • The chief administrator of a school. 

  • A diapason, a type of organ stop on a pipe organ. 

  • The construction that gives shape and strength to a roof, generally a truss of timber or iron; or, loosely, the most important member of a piece of framing. 

  • A dancer at the highest rank within a professional dance company, particularly a ballet company. 

  • The primary participant in a crime. 

  • The first two long feathers of a hawk's wing. 

  • A security principal. 

  • A legal person that authorizes another (the agent) to act on their behalf; or on whose behalf an agent or gestor in a negotiorum gestio acts. 

  • The chief executive and chief academic officer of a university or college. 

  • The money originally invested or loaned, on which basis interest and returns are calculated. 

  • A partner or owner of a business. 

  • One of the turrets or pinnacles of waxwork and tapers with which the posts and centre of a funeral hearse were formerly crowned 

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