heir-at-law vs heritor

heir-at-law

noun
  • A person legally entitled to inherit the property of someone who dies intestate. 

heritor

noun
  • A person who inherits; an heir or heiress. 

  • A proprietor or landholder in a parish. 

How often have the words heir-at-law and heritor occurred in a corpus of books? (source: Google Ngram Viewer )