horizontal vs in straight line

horizontal

noun
  • A horizontal component of a structure. 

  • Horizon. 

  • A Tasmanian shrub or small tree whose main trunk tends to lean over and grow horizontally, Anodopetalum biglandulosum 

adj
  • Relating to horizontal markets 

  • Involving wines of the same vintages but from different wineries. 

  • Having the two notes sound successively. 

  • Relating to sexual intercourse. 

  • Perpendicular to the vertical; parallel to the plane of the horizon; level, flat. 

in straight line

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