Privateer

A privateer was a privately-owned warship operating with the (overt or covert) tacit approval of a larger authority to attack and seize the shipping and property of designated enemies of that authority. The term was also applied to the captains and crew of such ships. In some cases privateers were sanctioned because the authority lacked the resources or infrastructure to support more conventional military forces. In other cases, privateers provided one entity with a means to harass its rivals while preserving deniability as to the source of that harassament.

In the strictest sense of the term "privateer", the "larger authority" was a national government which issued a formal license ("letter of marque", in traditional Earth terminology) to commit certain kinds of actions against certain targets of certain hostile governments. It was this formality that technically distinguished a privateer from a pirate. However, privateers were also employed by sub-national entities (Houses/Lines, local governments, Orion trading clans, corporations, etc.) as well, usually more covertly. This (and violations of the terms of their letters of marque by privateers) has resulted in an intertwining in the usage of the terms. (TOS novel: The Final Reflection; TNG novel: Blaze of Glory)