flaneur vs fly-by-night

flaneur

noun
  • One who wanders aimlessly, who roams, who travels at a lounging pace. 

  • An idler, a loafer. 

verb
  • To wander aimlessly or at a lounging pace. 

fly-by-night

noun
  • A person or business that appears and/or disappears rapidly, appearing untrustworthy, or giving an impression of transience. 

  • A traveling businessman or tradesman. 

  • A creature which flies at night; a nocturnal flier or traveler. 

  • One who departs or flees at night in order to avoid creditors, law enforcement etc. 

How often have the words flaneur and fly-by-night occurred in a corpus of books? (source: Google Ngram Viewer )