cacolet vs roughage

cacolet

noun
  • A single litter mounted on a pack animal. 

  • One of a pair of chairs or litters mounted on a pack animal (horse, mule, camel) 

roughage

noun
  • Coarse or rough plant material such as hay and silage used as animal fodder. 

  • Substances, generally of plant origin, consisting mostly of complex carbohydrates which are undigested when eaten by humans, and which therefore help the passage of food and waste through the alimentary tract; dietary fibre. 

  • Originally (archaic), garbage, rubbish, or waste; later (agriculture) the portions of a crop which are discarded, such as husks, stalks, etc.; also, agricultural waste such as weeds. 

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