executor vs intermediary

executor

noun
  • Someone appointed by a testator to administer a will; an administrator. 

  • A person who carries out some task. 

  • A component of a system that executes or runs something. 

intermediary

noun
  • An agent acting as a mediator between sides to facilitate agreement or cooperation. 

  • One or several stages of an event which occurs after the start and before the end. 

  • A person or organisation in an intermediate position (in a transaction, agreement, supply chain etc.) 

adj
  • Intermediate. 

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