grapevine vs mulga wire

grapevine

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

  • 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. 

  • A rumor. 

verb
  • To restrain in a leglock. 

mulga wire

noun
  • A message or story transmitted through such an informal network, especially one containing false information. 

  • A system for long-distance communication used by Aboriginal Australians, chiefly using smoke signals; also, a message or signal sent using such a system. 

  • An informal gossip network, especially in a rural area such as the outback; also, a component in the network (either a person or an imagined wire). 

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