purlieu vs suburb

purlieu

noun
  • The outskirts of any place; an adjacent district; the environs or neighborhood. 

  • The ground on the edges of a forest, especially when partly subject to the same forest laws concerning game hunting etc. 

suburb

noun
  • A residential area located on the outskirts of a city or large town that usually includes businesses that cater to its residents; such as schools, grocery stores, shopping centers, restaurants, convenience stores, etc. 

  • The outer part; the environment. 

  • Any subdivision of a conurbation, not necessarily on the periphery. 

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