An emissary is a representative sent by one government or leader to another. the President's special emissary to Hanoi. emissaries someone who is sent with an official message or to do official work = envoy
An agent employed to advance, in a covert manner, the interests of his employers; one sent out by any power that is at war with another, to create dissatisfaction among the people of the latter
Applied to the veins which pass out of the cranium through apertures in its walls