separate vs solitary

separate

adj
  • Not together (with); not united (to). 

  • Apart from (the rest); not connected to or attached to (anything else). 

verb
  • To disunite from a group or mass; to disconnect. 

  • To divide (a thing) into separate parts. 

  • To cause (things or people) to be separate. 

  • To divide itself into separate pieces or substances. 

noun
  • A printing of an article from a periodical as its own distinct publication and distributed independently, often with different page numbers. 

  • Anything that is sold by itself, especially articles of clothing such as blouses, skirts, jackets, and pants. 

solitary

adj
  • Living or being by oneself; alone; having no companion present 

  • Performed, passed, or endured alone 

  • Not much visited or frequented; remote from society 

  • Single; individual; sole. 

  • gloomy; dismal, because of not being inhabited. 

  • Not inhabited or occupied; without signs of inhabitants or occupation; desolate; deserted 

  • Not associated with others of the same kind. 

noun
  • One who lives alone, or in solitude; an anchorite, hermit or recluse. 

  • Solitary confinement. 

  • The state of being solitary; solitude 

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