clunge vs tunnel of love

clunge

noun
  • Vulva or vagina. 

  • Arse. 

tunnel of love

noun
  • The vagina. 

  • A carnival dark ride for couples in boats, either relaxing and romantic, or spooky (encouraging the couple to cling to one another). 

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