adscititious vs parenthetical

adscititious

adj
  • Derived or acquired from something extrinsic; not part of the real, inherent, or essential nature of a thing. 

parenthetical

adj
  • that explains or qualifies something 

  • that is incidental 

  • using, containing, or within parenthesis 

noun
  • A word or phrase within parentheses. 

  • A descriptor or modifier enclosed within parentheses and put, indented, in a line of dialogue to describe how it should be acted or directed onscreen. 

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