accessional vs adjunctive

accessional

adj
  • Pertaining to accession; additional. 

adjunctive

adj
  • additional; neither basic nor primary 

  • forming an adjunct 

  • the property of two operations x and y, such that ax(ayb) = a, and ay(axb) = a 

noun
  • a substance added as a supplement; often in the phrase "additives and adjunctives." 

  • a connector joining two components of the same weight, such as a coordinating conjunction 

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