rigid vs roughspun

rigid

adj
  • Rigorous and unbending. 

  • Stiff, rather than flexible. 

  • Fixed, rather than moving. 

  • Uncompromising. 

noun
  • An airship whose shape is maintained solely by an internal and/or external rigid structural framework, without using internal gas pressure to stiffen the vehicle (the lifting gas is at atmospheric pressure); typically also equipped with multiple redundant gasbags, unlike other types of airship. 

  • A bicycle with no suspension system. 

roughspun

adj
  • Unpolished, rough and ready, uncultured, unsophisticated. 

  • Woven from a coarsely spun yarn, (usually also from a coarse material). 

noun
  • A garment made from roughly spun yarn or made from a coarse material. 

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