accessorial vs adventitious

accessorial

adj
  • Of or pertaining to an accessory, e.g. to a crime. 

  • Of or relating to an accession. 

  • Assessorial. 

noun
  • An assessorial charge. 

adventitious

adj
  • Developing in an unusual place or from an unusual source. 

  • From an external source; not innate or inherent, foreign. 

  • Accidental, additional, appearing casually. 

  • Not congenital; acquired. 

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