accessary vs concomitant

accessary

adj
  • Accompanying as a subordinate; additional; accessory; especially, uniting in, or contributing to, a crime, but not as chief actor. See accessory. 

noun
  • Someone who accedes to some act, now especially a crime; one who contributes as an assistant or instigator to the commission of an offense. 

concomitant

adj
  • Accompanying; conjoining; attending; concurrent. 

  • Of or relating to the grammatical aspect which expresses that a secondary action is occurring simultaneously to the primary action of the statement. 

noun
  • An invariant homogeneous polynomial in the coefficients of a form, a covariant variable, and a contravariant variable. 

  • Something happening or existing at the same time. 

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