subalternate vs underground

subalternate

adj
  • Subaltern; inferior; subordinate. 

  • Succeeding by turns; successive. 

noun
  • A particular proposition, as opposed to a universal one. 

underground

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

  • Hidden, furtive, secretive. 

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

verb
  • To route electricity distribution cables underground. 

adv
  • Below the ground. 

  • Secretly. 

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. 

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