supercargo

noun4

1. •
   (historical) An officer on board a merchant ship who is in charge of the cargo and its sale; if there are two such officers, the senior one, the other being the subcargo.
2. •
   (figurative) Any overseer or superintendent; also, an agent or representative; or an intermediary; a go-between, a middleman.
3. •
   Synonym of supracargo
4. •
   (no longer used) An agent or representative of a company in charge of its overseas business.