grist vs iota

grist

noun
  • A given size of rope, common grist being a rope three inches in circumference, with twenty yarns in each of the three strands. 

  • Grain that is to be ground in a mill. 

verb
  • To grind in a mill. 

iota

noun
  • The ninth letter of the Greek alphabet. 

  • A jot; a very small, insignificant quantity. 

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