be quiet vs pipe down

be quiet

intj
  • Remain silent. 

pipe down

verb
  • To be quiet; to refrain from being noisy. 

  • To dismiss from muster, as a ship's company. 

  • Of a man, to have penetrative sex with a woman. 

How often have the words be quiet and pipe down occurred in a corpus of books? (source: Google Ngram Viewer )