These are not a tradition so much as the container the period used to hold everyone outside the Abrahamic faiths. Adams inherits a fourfold map of the religious world, Christians, Jews, Muslims, and Pagans or Heathens, in which the last and largest category gathers the entire non-monotheistic world. Understanding how she draws that box explains how every reservoir tradition in this archive is filed.
Her Pagans entry then subdivides the box into four classes, from the Greeks and Romans through the ancient nations, the Asian religions, and the peoples she calls barbarians, and lists what they worship, beginning with the heavenly bodies. The Chaldeans, Phenicians, and Sabians, the archive’s own material, sit in her second class.
In Hannah Adams
In Adams’s own words, from the 1817 Dictionary. Each passage is quoted verbatim under its own entry.
HEATHEN, a term which, like Gentiles, was applied formerly to all nations but the Jews, and is still applicable to all pagan nations.
GENTILES, a term which the Jews applied to all foreigners; so the Greeks called all other nations barbarians.
Hannah Adams, A Dictionary of All Religions and Religious Denominations, 4th ed. (Boston: Cummings and Hilliard, 1817), entries “Heathen” (p. 104), “Gentiles” (p. 95).