demurral vs demurrer

demurral

noun
  • The act of demurring. 

  • A formal objection. 

demurrer

noun
  • Someone who demurs. 

  • A motion by a party to an action, for the immediate or summary judgment of the court on the question, whether, assuming the truth of the matter alleged by the opposite party, it is sufficient in law to sustain the action or defense, and hence whether the party resting is bound to answer or proceed further. 

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