ding-a-ling vs skin flute

ding-a-ling

noun

  • The penis. 

  • An eccentric or crazy person. 

  • The sound of a small bell; the sound of a fire engine bell. 

adj

  • Attractive. 

skin flute

noun

  • A penis. 

How often have the words ding-a-ling and skin flute occurred in a corpus of books? (source: Google Ngram Viewer )