sleep-in vs walkout

sleep-in

noun
  • An instance of sleeping in, sleeping late, sleeping until one feels fully refreshed rather than rising at a prespecified time. 

walkout

noun
  • A sudden stoppage of work. 

  • A similar mass action of people leaving a place as a form of protest. 

  • A part of the squat exercise wherein one has to step out from the rack (“walk out” the weight) in order not to hit it during execution. 

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