lad vs little head

lad

noun

  • The penis. 

  • A boy or young man. 

  • A groom who works with horses. 

  • A Jack the lad; a boyo. 

  • A familiar term of address for a young man. 

little head

noun

  • The glans of the penis. 

How often have the words lad and little head occurred in a corpus of books? (source: Google Ngram Viewer )