imperfection vs nonesuch

imperfection

noun
  • Those qualities or features that are imperfect; the characteristic, state, or quality of being imperfect. 

  • Something that makes something else less than perfect; a blemish, impurity, error, etc. 

nonesuch

noun
  • Silene chalcedonica (syn. Lychnis chalcedonica) 

  • A person or thing with no equal. 

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