air vs natural gas

air

noun
  • understood as a gaseous mixture of nitrogen, oxygen, and various trace gases. 

  • The apparently open space above the ground which this substance fills, (historical) formerly thought to be limited by the firmament but (meteorology) now considered to be surrounded by the near vacuum of outer space. 

  • understood as a particular local substance with supposed effects on human health. 

  • A song, especially a solo; an aria. 

  • A jump in which one becomes airborne. 

  • A feeling or sense. 

  • The substance constituting Earth's atmosphere 

  • A sense of poise, graciousness, or quality. 

  • Nothing; absence of anything. 

  • Publicity. 

  • A breeze; a gentle wind. 

  • A television or radio signal; (by extension) media broadcasts in general. 

  • An air conditioner or the processed air it produces. 

  • understood as one of the four elements of the ancient Greeks and Romans. 

  • Pretension; snobbishness; pretence that one is better than others. 

verb
  • To be broadcast. 

  • To broadcast (a television show etc.). 

  • To discuss varying viewpoints on a given topic. 

  • To bring (something) into contact with the air, so as to freshen or dry it. 

  • To ignore (a person). 

  • To let fresh air into a room or a building, to ventilate. 

natural gas

noun
  • A mixture of gaseous hydrocarbons associated with petroleum deposits; mostly methane with smaller amounts of ethane, propane and butane; principally used as a fuel. 

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