singlefold vs unsound

singlefold

adj
  • Consisting of a single fold or undivided part. 

unsound

adj
  • Not whole, not solid, defective. 

  • Infirm, diseased. 

  • Not good, unreliable. 

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