rolling stone vs rough sleeper

rolling stone

noun
  • A person who moves around a lot and never settles down; a vagrant. 

  • A geological phenomenon where rocks move and inscribe long tracks along a smooth valley floor without animal or human intervention. 

  • A meteoroid. 

  • A womanizer. 

rough sleeper

noun
  • A homeless person who sleeps outdoors. 

How often have the words rolling stone and rough sleeper occurred in a corpus of books? (source: Google Ngram Viewer )