caution vs walk heavy

caution

verb
  • To warn; to alert, advise that caution is warranted. 

  • To give a yellow card 

noun
  • A formal warning given as an alternative to prosecution in minor cases. 

  • Security; guaranty; bail. 

  • A yellow card. 

  • Prudence when faced with, or when expecting to face, danger; care taken in order to avoid risk or harm. 

  • A careful attention to the probable effects of an act, in order that failure or harm may be avoided. 

walk heavy

How often have the words caution and walk heavy occurred in a corpus of books? (source: Google Ngram Viewer )