back-alley vs lowdown

back-alley

adj
  • Occurring away from publicity, or in mean surroundings; backstreet. 

lowdown

adj
  • Unfair; shameful. 

  • down low; purporting to be heterosexual while engaged in sex with men. 

noun
  • inside information, the story or truth. 

  • A lowlife, a despicable person. 

How often have the words back-alley and lowdown occurred in a corpus of books? (source: Google Ngram Viewer )