Best to limit the word to the worship of natural objects revered not for their own power, but because they are occupied by a spirit.
Nassau, R. H. . Fetichism in West Africa. New York: Negro Universities Press. 1969 (1904):81
[The worship of] an intangible power or spirit incorporated in some visible form.
Haddon, A. C. Magic and fetishism. London: Constable. 1921:70