Zip vs mongrel

Zip

noun
  • A Sicilian or Italian Mafioso who is relatively new to the United States. 

mongrel

noun
  • A thuggish, obnoxious, or contemptible person; (often preceded by "poor") a pitiable person. 

  • Someone or something of mixed kind or uncertain origin, especially a dog. 

  • An erect penis; an erection. 

adj
  • Of mixed breed, nature, or origin; of or like a mongrel. 

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