dirty laundry vs grapevine

dirty laundry

noun
  • Unflattering or embarrassing facts, or questionable activities that one wants to remain secret, but which someone else may use as blackmail. 

  • Used other than figuratively or idiomatically: see dirty, laundry. 

  • A clothes hamper or other container in which soiled laundry is placed. 

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. 

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