codicillary vs referential

codicillary

adj
  • Of or pertaining to a codicil. 

referential

adj
  • Of or relating to a referent. 

  • Serving as a reference. 

  • Of a word or phrase applied to a particular person, place, or thing and not to any other. 

  • Of or relating to reference or allusion. 

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