cupreous vs dun

cupreous

adj
  • Of a reddish-brown color, like that of polished copper. 

  • Of or of the nature of copper. 

  • Containing copper. 

noun
  • A reddish-brown color, like that of polished copper. 

dun

adj
  • Of a brownish grey colour. 

verb
  • To harass by continually repeating e.g. a request. 

  • To ask or beset a debtor for payment. 

noun
  • A collector of debts, especially one who is insistent and demanding. 

  • A fly made to resemble the mayfly subimago. 

  • A newly hatched, immature mayfly; a mayfly subimago. 

  • An ancient or medieval fortification; especially a hill-fort in Scotland or Ireland. 

  • A mound or small hill. 

  • A brownish grey colour. 

  • An urgent request or demand of payment. 

  • A structure in the Orkney or Shetland islands or in Scotland consisting of a roundhouse surrounded by a circular wall; a broch. 

intj
  • Imitating a deep bass note, such as that found in suspenseful music. 

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