compurgator vs plaintiff

compurgator

noun
  • An ‘oath-helper’ in Anglo-Saxon or Germanic law who testified to the character of an accused person. 

  • A character witness in canon law who swore an oath that the accused was innocent. 

plaintiff

noun
  • A party bringing a suit in civil law against a defendant; accuser. 

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