decern vs ken

decern

verb
  • See distinctly (with the eyes or the mind); distinguish (an object or fact); discern. 

  • transferred sense 

  • Decree a person etc. to be or to do something by judicial sentence.  (in the phrase “to decern in”, obsolete) To mulct in by decree of court. 

  • Decree by judicial sentence that something be done. 

  • intransitive 

  • with simple object 

ken

verb
  • To know, perceive or understand. 

noun
  • Youth or children's group. 

  • A Japanese unit of length equal to six shakus 

  • Range of sight. 

  • Knowledge, perception, or sight. 

  • The tsurugi 

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