frail vs ultra-thin

frail

verb
  • To play a stringed instrument, usually a banjo, by picking with the back of a fingernail. 

noun
  • A basket made of rushes, used chiefly to hold figs and raisins. 

  • A rush for weaving baskets. 

  • The quantity of fruit or other items contained in a frail. 

adj
  • Mentally fragile. 

  • Weak; infirm. 

  • Liable to fall from virtue or be led into sin; not strong against temptation; weak in resolution; unchaste. 

  • Easily broken physically; not firm or durable; liable to fail and perish. 

ultra-thin

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