fetish

noun
an object (such as a small stone carving of an animal) believed to have magical power to protect or aid its owner; broadly : a material object regarded with superstitious or extravagant trust or reverence
an object of irrational reverence or obsessive devotion : prepossession
an object or bodily part whose real or fantasied presence is psychologically necessary for sexual gratification and that is an object of fixation to the extent that it may interfere with complete sexual expression