The Collaborative International Dictionary of English v.0.48:

Idolatry \I*dol"a*try\, n.; pl. Idolatries. [F. idol[^a]trie,
   LL. idolatria, L. idololatria, Fr. Gr. ?; ? idol + ?
   service.]
   1. The worship of idols, images, or anything which is not
      God; the worship of false gods.
      [1913 Webster]

            His eye surveyed the dark idolatries
            Of alienated Judah.                   --Milton.
      [1913 Webster]

   2. Excessive attachment or veneration for anything; respect
      or love which borders on adoration. --Shak.
      [1913 Webster]

WordNet (r) 3.0 (2006):

idolatry
    n 1: religious zeal; the willingness to serve God [syn:
         idolatry, devotion, veneration, cultism]
    2: the worship of idols; the worship of images that are not God
       [syn: idolatry, idol worship]

Moby Thesaurus II by Grady Ward, 1.0:

129 Moby Thesaurus words for "idolatry":
   Amor, Christian love, Eros, Platonic love, accolade, admiration,
   adoration, adulation, affection, agape, allotheism, animatism,
   animism, anthropolatry, apotheosis, appreciation, approbation,
   approval, arborolatry, ardency, ardor, attachment, awe,
   bepraisement, bibliolatry, bodily love, breathless adoration,
   brotherly love, caritas, charity, congratulation, conjugal love,
   consideration, courtesy, deference, deification, demonolatry,
   desire, devotion, duty, eloge, encomium, esteem, estimation,
   eulogium, eulogy, exaggerated respect, exaltation,
   excessive praise, faithful love, fancy, favor, fervor, flame,
   flattery, fondness, free love, free-lovism, glorification, glory,
   great respect, heart, heathendom, heathenism, heathenry,
   hero worship, high regard, homage, hommage, honor, hygeiolatry,
   iconolatry, idolism, idolization, idolizing, kudos, lasciviousness,
   laud, laudation, libido, like, liking, lionizing, litholatry, love,
   lovemaking, magnification, married love, meed of praise, monolatry,
   ophiolatry, overcommendation, overestimation, overlaudation,
   overpraise, overprizing, paean, pagandom, paganism, paganry,
   panegyric, passion, patriolatry, physical love, physiolatry,
   phytolatry, popular regard, popularity, praise, prestige,
   pyrolatry, regard, respect, reverence, reverential regard,
   sentiment, sex, sexual love, shine, spiritual love, tender feeling,
   tender passion, tribute, truelove, uxoriousness, veneration,
   weakness, worship, yearning



Easton's 1897 Bible Dictionary:

Idolatry
   image-worship or divine honour paid to any created object. Paul
   describes the origin of idolatry in Rom. 1:21-25: men forsook
   God, and sank into ignorance and moral corruption (1:28).

     The forms of idolatry are, (1.) Fetishism, or the worship of
   trees, rivers, hills, stones, etc.

     (2.) Nature worship, the worship of the sun, moon, and stars,
   as the supposed powers of nature.

     (3.) Hero worship, the worship of deceased ancestors, or of
   heroes.

     In Scripture, idolatry is regarded as of heathen origin, and
   as being imported among the Hebrews through contact with heathen
   nations. The first allusion to idolatry is in the account of
   Rachel stealing her father's teraphim (Gen. 31:19), which were
   the relics of the worship of other gods by Laban's progenitors
   "on the other side of the river in old time" (Josh. 24:2).
   During their long residence in Egypt the Hebrews fell into
   idolatry, and it was long before they were delivered from it
   (Josh. 24:14; Ezek. 20:7). Many a token of God's displeasure
   fell upon them because of this sin.

     The idolatry learned in Egypt was probably rooted out from
   among the people during the forty years' wanderings; but when
   the Jews entered Palestine, they came into contact with the
   monuments and associations of the idolatry of the old
   Canaanitish races, and showed a constant tendency to depart from
   the living God and follow the idolatrous practices of those
   heathen nations. It was their great national sin, which was only
   effectually rebuked by the Babylonian exile. That exile finally
   purified the Jews of all idolatrous tendencies.

     The first and second commandments are directed against
   idolatry of every form. Individuals and communities were equally
   amenable to the rigorous code. The individual offender was
   devoted to destruction (Ex. 22:20). His nearest relatives were
   not only bound to denounce him and deliver him up to punishment
   (Deut. 13:20-10), but their hands were to strike the first blow
   when, on the evidence of two witnesses at least, he was stoned
   (Deut. 17:2-7). To attempt to seduce others to false worship was
   a crime of equal enormity (13:6-10). An idolatrous nation shared
   the same fate. No facts are more strongly declared in the Old
   Testament than that the extermination of the Canaanites was the
   punishment of their idolatry (Ex. 34:15, 16; Deut. 7; 12:29-31;
   20:17), and that the calamities of the Israelites were due to
   the same cause (Jer. 2:17). "A city guilty of idolatry was
   looked upon as a cancer in the state; it was considered to be in
   rebellion, and treated according to the laws of war. Its
   inhabitants and all their cattle were put to death." Jehovah was
   the theocratic King of Israel, the civil Head of the
   commonwealth, and therefore to an Israelite idolatry was a state
   offence (1 Sam. 15:23), high treason. On taking possession of
   the land, the Jews were commanded to destroy all traces of every
   kind of the existing idolatry of the Canaanites (Ex. 23:24, 32;
   34:13; Deut. 7:5, 25; 12:1-3).

     In the New Testament the term idolatry is used to designate
   covetousness (Matt. 6:24; Luke 16:13; Col. 3:5; Eph. 5:5).