unapprehended vs undistinguished

unapprehended

adj
  • Not understood. 

  • Not apprehended. 

undistinguished

adj
  • Not distinguished: not having an air of distinction. 

  • Not distinguished: not marked by conspicuous qualities. 

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