join vs separate

join

verb
  • To connect or combine into one; to put together. 

  • To unite in marriage. 

  • To produce an intersection of data in two or more database tables. 

  • To come into the company of. 

  • To come together; to meet. 

  • To accept, or engage in, as a contest. 

  • To become a member of. 

  • To enter into association or alliance, to unite in a common purpose. 

noun
  • An intersection of data in two or more database tables. 

  • The act of joining something, such as a network. 

  • The lowest upper bound, an operation between pairs of elements in a lattice, denoted by the symbol ∨. 

  • An intersection of piping or wiring; an interconnect. 

separate

verb
  • To divide (a thing) into separate parts. 

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

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

  • To divide itself into separate pieces or substances. 

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

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

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. 

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