cardinal vs mainline

cardinal

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

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

  • 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. 

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  • A woman's short cloak with a hood, originally made of scarlet cloth.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

mainline

adj
  • Of or pertaining to the principal route or line of a railway. 

  • Normal, principal or standard. 

  • Of or pertaining to a surface railway as distinct from an underground, elevated or light rail one. 

  • Of a sequence of opening moves: being part of a main line ("a standard sequence of opening moves considered to be best play"). 

verb
  • To integrate (code, etc.) into the main repository for a software project, rather than separate forks. 

  • To inject (a drug) directly into a vein. 

  • To consume voraciously. 

noun
  • In longline fishing the central line to which the branch lines with baits are attached. 

  • An airline's main operating unit, as opposed to codeshares or regional subsidiaries. 

  • The principal route or line of a railway. 

  • A principal vein into which a drug can be injected. 

  • The main repository for a software project, from which different versions (forks) may be split off. 

  • The pipeline carrying wastewater to the public drains or a septic tank. 

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