The Collaborative International Dictionary of English v.0.48:

Idol \I"dol\, n. [OE. idole, F. idole, L. idolum, fr. Gr. ?, fr.
   ? that which is seen, the form, shape, figure, fr. ? to see.
   See Wit, and cf. Eidolon.]
   1. An image or representation of anything. [Obs.]
      [1913 Webster]

            Do her adore with sacred reverence,
            As th' idol of her maker's great magnificence.
                                                  --Spenser.
      [1913 Webster]

   2. An image of a divinity; a representation or symbol of a
      deity or any other being or thing, made or used as an
      object of worship; a similitude of a false god.
      [1913 Webster]

            That they should not worship devils, and idols of
            gold.                                 --Rev. ix. 20.
      [1913 Webster]

   3. That on which the affections are strongly (often
      excessively) set; an object of passionate devotion; a
      person or thing greatly loved or adored.
      [1913 Webster]

            The soldier's god and people's idol.  --Denham.
      [1913 Webster]

   4. A false notion or conception; a fallacy. --Bacon.
      [1913 Webster]

            The idols of preconceived opinion.    --Coleridge.
      [1913 Webster]

WordNet (r) 3.0 (2006):

idol
    n 1: a material effigy that is worshipped; "thou shalt not make
         unto thee any graven image"; "money was his god" [syn:
         idol, graven image, god]
    2: someone who is adored blindly and excessively [syn: idol,
       matinee idol]
    3: an ideal instance; a perfect embodiment of a concept [syn:
       paragon, idol, perfection, beau ideal]

Moby Thesaurus II by Grady Ward, 1.0:

101 Moby Thesaurus words for "idol":
   Baal, Juggernaut, big name, celebrity, companion, constellation,
   copy, cosset, cynosure, darling, dea, dead ringer, deity, demigod,
   demigoddess, deus, deva, devi, devil-god, divinity, double,
   duplicate, effigy, exact likeness, false god, favorite, fellow,
   fetish, figure, folk hero, fondling, galaxy, god, goddess,
   golden calf, graven image, great man, heathen god, hero, heroine,
   icon, ikon, image, immortal, important person, jewel, joss,
   likeness, lion, living image, living picture, luminaries, luminary,
   man of mark, master spirit, match, mate, matinee idol, miniature,
   minion, mirroring, model, name, notability, notable, pagan deity,
   person of note, personage, pet, phoenix, photograph, picture,
   pleiad, pop hero, popular hero, popular idol, portrait, preference,
   public figure, reflection, resemblance, rubbing, semblance, shadow,
   similitude, simulacrum, social lion, somebody, spit and image,
   spitting image, spoiled child, star, superstar, symbol,
   the shining ones, trace, tracing, twin, very image, very picture,
   worthy



The Free On-line Dictionary of Computing (30 December 2018):

IDOL

   Icon-Derived Object Language.  An object-oriented
   preprocessor for Icon.

   (ftp://src.doc.ic.ac.uk/pub/languages/icon/idol.tar.Z).

   ["Programming in Idol: An Object Primer", C.L. Jeffery, U
   Arizona CS TR #90-10].


Easton's 1897 Bible Dictionary:

Idol
   (1.) Heb. aven, "nothingness;" "vanity" (Isa. 66:3; 41:29; Deut.
   32:21; 1 Kings 16:13; Ps. 31:6; Jer. 8:19, etc.).

     (2.) 'Elil, "a thing of naught" (Ps. 97:7; Isa. 19:3); a word
   of contempt, used of the gods of Noph (Ezek. 30:13).

     (3.) 'Emah, "terror," in allusion to the hideous form of idols
   (Jer. 50:38).

     (4.) Miphletzeth, "a fright;" "horror" (1 Kings 15:13; 2 Chr.
   15:16).

     (5.) Bosheth, "shame;" "shameful thing" (Jer. 11:13; Hos.
   9:10); as characterizing the obscenity of the worship of Baal.

     (6.) Gillulim, also a word of contempt, "dung;" "refuse"
   (Ezek. 16:36; 20:8; Deut. 29:17, marg.).

     (7.) Shikkuts, "filth;" "impurity" (Ezek. 37:23; Nah. 3:6).

     (8.) Semel, "likeness;" "a carved image" (Deut. 4:16).

     (9.) Tselem, "a shadow" (Dan. 3:1; 1 Sam. 6:5), as
   distinguished from the "likeness," or the exact counterpart.

     (10.) Temunah, "similitude" (Deut. 4:12-19). Here Moses
   forbids the several forms of Gentile idolatry.

     (11.) 'Atsab, "a figure;" from the root "to fashion," "to
   labour;" denoting that idols are the result of man's labour
   (Isa. 48:5; Ps. 139:24, "wicked way;" literally, as some
   translate, "way of an idol").

     (12.) Tsir, "a form;" "shape" (Isa. 45:16).

     (13.) Matztzebah, a "statue" set up (Jer. 43:13); a memorial
   stone like that erected by Jacob (Gen. 28:18; 31:45; 35:14, 20),
   by Joshua (4:9), and by Samuel (1 Sam. 7:12). It is the name
   given to the statues of Baal (2 Kings 3:2; 10:27).

     (14.) Hammanim, "sun-images." Hamman is a synonym of Baal, the
   sun-god of the Phoenicians (2 Chr. 34:4, 7; 14:3, 5; Isa. 17:8).

     (15.) Maskith, "device" (Lev. 26:1; Num. 33:52). In Lev. 26:1,
   the words "image of stone" (A.V.) denote "a stone or cippus with
   the image of an idol, as Baal, Astarte, etc." In Ezek. 8:12,
   "chambers of imagery" (maskith), are "chambers of which the
   walls are painted with the figures of idols;" comp. ver. 10, 11.

     (16.) Pesel, "a graven" or "carved image" (Isa. 44:10-20). It
   denotes also a figure cast in metal (Deut. 7:25; 27:15; Isa.
   40:19; 44:10).

     (17.) Massekah, "a molten image" (Deut. 9:12; Judg. 17:3, 4).

     (18.) Teraphim, pl., "images," family gods (penates)
   worshipped by Abram's kindred (Josh. 24:14). Put by Michal in
   David's bed (Judg. 17:5; 18:14, 17, 18, 20; 1 Sam. 19:13).

     "Nothing can be more instructive and significant than this
   multiplicity and variety of words designating the instruments
   and inventions of idolatry."