Real Dictionary

cargo cult in American English
a quasi-religious cult among some South Sea islanders, based on a belief that the spirits of their ancestors will return with supplies of modern goods, thus inaugurating a golden age of prosperity and, sometimes, liberation from colonial domination
noun: any of various native religious cults of a millenarian and messianic character located in the southwestern Pacific islands, holding that spirits will bring large cargoes of modern goods for distribution among its adherents

cargo cult in British English
noun: a religious movement of the SW Pacific, characterized by expectation of the return of spirits in ships or aircraft carrying goods that will provide for the needs of the followers