grease vs slush fund

grease

noun
  • bribe money. 

  • Any oily or fatty matter. 

  • Shorn but not yet cleansed wool. 

  • Inflammation of a horse's heels, also known as scratches or pastern dermatitis. 

  • Animal fat in a melted or soft state. 

verb
  • To kill, murder. 

  • To cause to go easily; to facilitate. 

  • To affect (a horse) with grease, the disease. 

  • To perform a landing extraordinarily smoothly. 

  • To put grease or fat on something, especially in order to lubricate. 

  • To bribe. 

slush fund

noun
  • Money stored for illegal or dishonest purposes. 

  • Money that has not been hypothecated or dedicated to a particular purpose, or which is used for a different purpose than originally intended. 

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