assent vs red light

assent

noun
  • agreement; act of agreeing 

verb
  • To agree to a proposal. 

red light

noun
  • A warning light, especially as a traffic signal indicating stop. 

  • Denial to proceed; a ruling out of any possibility. 

  • A sign of a brothel. 

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