idolyoudaoicibaDictYouDict[idol 词源字典]
idol: [13] Greek eidos meant ‘form, shape’ (it came from the same root as idéā, source of English idea). From it was derived eídōlon, which originally meant ‘appearance’, and in particular ‘apparition, phantom’. It developed from there to ‘image’, either a ‘mental image’ or a ‘physical image’, such as a ‘statue’; and in the early Christian era it and its Latin descendant īdōlum were used for an ‘image of a false god’.

English acquired the word via Old French idole or idele. Another English offspring of Greek eidos, in the sense ‘picture’, is idyll [17], which was borrowed from the diminutive form eidúllion ‘little picture’, hence ‘small descriptive poem’.
=> idea, idyll[idol etymology, idol origin, 英语词源]
idol (n.)youdaoicibaDictYouDict
mid-13c., "image of a deity as an object of (pagan) worship," from Old French idole "idol, graven image, pagan god," from Late Latin idolum "image (mental or physical), form," used in Church Latin for "false god," from Greek eidolon "appearance, reflection in water or a mirror," later "mental image, apparition, phantom," also "material image, statue," from eidos "form" (see -oid). Figurative sense of "something idolized" is first recorded 1560s (in Middle English the figurative sense was "someone who is false or untrustworthy"). Meaning "a person so adored" is from 1590s.