grapevine vs interconnected system

grapevine

verb
  • To restrain in a leglock. 

noun
  • A leglock. 

  • The plant, a vine of genus Vitis, on which grapes grow. 

  • A move in which the feet are alternately placed in front of each other, while both remaining on the ice or ground, incorporating half-turns. 

  • An informal person-to-person means of circulating information or gossip. 

  • A rumor. 

interconnected system

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