cocksack vs scrotum

cocksack

noun
  • The scrotum. 

  • Clothing that covers the scrotum in a manner similar to a codpiece. 

  • A term of abuse. 

scrotum

noun
  • The sac of skin and muscle that contains the testicles in most mammals. 

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