an officer on a merchant ship who has charge of the cargo and the business dealings of the voyage
See supercargo in American Heritage Dictionary 4
su·per·car·go
nounpl.supercargoessu·per·car·goes or su·per·car·gos
An officer on a merchant ship who has charge of the cargo and its sale and purchase.
Origin: Alteration (influenced by super-) of supracargo, alteration (influenced by supra-) of Spanish sobrecargo : sobre-, over (from Latin super-; see super- ) + cargo, cargo; see cargo .