cardinal vs heliotrope

cardinal

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

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  • A woman's short cloak with a hood, originally made of scarlet cloth. 

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

adj
  • 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. 

  • Of fundamental importance; crucial, pivotal. 

heliotrope

noun
  • A light purple or violet colour. 

  • Particularly, a purple-flowered plant of the species Heliotropium arborescens. 

  • A bloodstone (a variety of quartz). 

  • An instrument, employed in triangulation, that uses a mirror to reflect sunlight toward another, very distant, surveyor. 

  • The fragrance of heliotrope flowers. 

  • A plant that turns so that it faces the sun. 

adj
  • Light purple or violet. 

  • Keeping one’s face turned toward the sun. 

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