impute vs unnoble

impute

verb
  • To ascribe (sin or righteousness) to someone by substitution. 

  • To attribute or ascribe (responsibility or fault) to a cause or source. 

  • To replace missing data with substituted values. 

  • To take into account. 

  • To attribute or credit to. 

unnoble

verb
  • To make (someone or something) no longer noble 

adj
  • Not noble; ignoble; base. 

  • Of a metal, being at the lower end of the electrochemical series, i.e. oxidising readily. 

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