erroneous vs unretentive

erroneous

adj
  • Mistaken. 

  • Derived from an error. 

  • Containing an error; inaccurate. 

  • Deviating from the requirements of the law, but without a lack of legal authority, thus not illegal. 

unretentive

adj
  • Not retentive 

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