In Middle English it was secretarie and in Middle Latin it was secretarius . Probably the earliest use of the word was in relation to those people who acted for a king. A king would have his trusted agents handle correspondence on private or secret matters, particularly matters of state. A person employed by a public body, or by a company or by an individual, to write orders, letters, dispatches, public or private papers, records, and the like. Thus legislative bodies have secretaries whose business is to record all their laws and resolves.
Ambassadors have secretaries.