cocksack vs knapsack

cocksack

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

  • The scrotum. 

  • A term of abuse. 

knapsack

noun
  • A case of canvas or leather, for carrying items on the back. 

  • A set of values from which a subset is chosen. 

verb
  • To go hiking while burdened with a knapsack, usually overnight or for longer. 

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