hairline vs vaporous

hairline

adj
  • very thin, as thin as a hair 

noun
  • A fishing line made from hair. 

  • The line along one's forehead where hair starts growing. 

  • A very thin line in writing, drawing, or typography. 

  • A very thin fissure. 

vaporous

adj
  • Of clothes or fabric: thin and translucent; filmy, gauzy. 

  • Of a thing: covered or hidden by vapour, fog, or mist. 

  • Of a place: filled with vapour; foggy, misty. 

  • Breathing out or giving off vapour. 

  • Of or relating to vapour; also, having the characteristics or consistency of vapour. 

  • Lacking depth or substance; insubstantial, thoughtless, vague. 

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