WordNet (r) 3.0 (2006):

idol worship
    n 1: the worship of idols; the worship of images that are not
         God [syn: idolatry, idol worship]

Moby Thesaurus II by Grady Ward, 1.0:

28 Moby Thesaurus words for "idol worship":
   Druidism, Parsiism, Sabaism, Zoroastrianism, animal worship,
   demonism, demonolatry, devil worship, fetishism, fire worship,
   heathenism, hero worship, iconoduly, iconolatry, idolatrousness,
   idolatry, idolism, idolodulia, idolomancy, image worship, paganism,
   phallic worship, phallicism, pyrolatry, snake worship,
   star worship, sun worship, tree worship