clew vs duff

clew

verb
  • to roll into a ball 

  • (transitive and intransitive) to raise the lower corner(s) of (a sail) 

noun
  • Yarn or thread as used to guide one's way through a maze or labyrinth; a guide, a clue. 

  • The cords suspending a hammock. 

  • The sheets so attached to a sail. 

  • The lower corner(s) of a sail to which a sheet is attached for trimming the sail (adjusting its position relative to the wind); the metal loop or cringle in the corner of the sail, to which the sheet is attached. (on a triangular sail) The trailing corner relative to the wind direction. 

duff

verb
  • To hit the ground behind the ball. 

  • To alter the branding of stolen cattle; to steal cattle. 

adj
  • Worthless; not working properly, defective. 

noun
  • A mixture of coal and rock. 

  • A pudding-style dessert, especially one made with plums. 

  • The bits left in the bottom of the bag after the booty has been consumed, like crumbs. 

  • Something spurious or fake; a counterfeit, a worthless thing. 

  • An error. 

  • A stiff flour pudding, often with dried fruit, boiled in a cloth bag, or steamed. 

  • Fine and dry coal in small pieces, usually anthracite. 

  • Dough. 

  • Decaying vegetable matter on the forest floor. 

  • Coal dust, especially that left after screening or combined with other small, unsaleable bits of coal. 

  • The buttocks. 

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