above ground vs underground

above ground

prep
  • Not dead and buried; alive. 

  • Not of or relating to the social or political underground; in the open; existing within or produced by the establishment. 

  • On or above the surface of the ground. 

underground

noun
  • A movement or organisation of people who resist artistic convention. 

  • A movement or organisation of people who resist political convention. 

  • Regions beneath the surface of the earth, both natural (eg. caves) and man-made (eg. mines). 

  • Synonym of subway: a railway that is under the ground. 

adv
  • Below the ground. 

  • Secretly. 

verb
  • To route electricity distribution cables underground. 

adj
  • Hidden, furtive, secretive. 

  • Below the ground; below the surface of the Earth. 

  • Outside the mainstream, especially unofficial and hidden from the authorities. 

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