bast vs chaff

bast

noun
  • Fibre made from the phloem of certain plants and used for matting and cord. 

chaff

noun
  • The inedible parts of a grain-producing plant. 

  • Light jesting talk; banter; raillery. 

  • Any excess or unwanted material, resource, or person; anything worthless. 

  • Loose material, e.g. small strips of aluminum foil dropped from aircraft, intended to interfere with radar detection. 

  • Straw or hay cut up fine for the food of cattle. 

verb
  • To use light, idle language by way of fun or ridicule; to banter. 

  • To make fun of; to turn into ridicule by addressing in ironical or bantering language; to quiz. 

  • To cut up (straw or hay) for use as cattle feed. 

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