lie-in vs sit-in

lie-in

noun
  • A form of protest where a group of people lie down in a public area. 

  • A period spent lying in bed for longer than usual after one has woken up. 

sit-in

noun
  • A peaceful form of protest in which people occupy an area and refuse to leave. 

adj
  • Designed to be sat in. 

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