NOUN (2)

1. (Melanesia) the followers of one of several millenarian cults that believe salvation will come in the form of wealth (`cargo') brought by westerners; some ascribe divine attributes to westerners on first contact (especially to missionaries);

2. a religious cult that anticipates a time of joy, serenity, and justice when salvation comes;

WordNet (r) 3.0 (2006):

cargo cult
    n 1: (Melanesia) the followers of one of several millenarian
         cults that believe salvation will come in the form of
         wealth (`cargo') brought by westerners; some ascribe divine
         attributes to westerners on first contact (especially to
         missionaries)
    2: a religious cult that anticipates a time of joy, serenity,
       and justice when salvation comes