butt-fucking vs clacker

butt-fucking

noun

  • anal sex 

adj

  • Engaging in anal sex 

clacker

noun

  • The anus. 

  • Any device that makes a clacking noise. 

  • A percussion instrument that makes a clacking noise. 

How often have the words butt-fucking and clacker occurred in a corpus of books? (source: Google Ngram Viewer )