The Collaborative International Dictionary of English v.0.48:

Anathema \A*nath"e*ma\, n.; pl. Anathemas. [L. anath[e^]ma,
   fr. Gr. ? anything devoted, esp. to evil, a curse; also L.
   anath[=e]ma, fr. Gr. ? a votive offering; all fr. ? to set up
   as a votive gift, dedicate; ? up + ? to set. See Thesis.]
   1. A ban or curse pronounced with religious solemnity by
      ecclesiastical authority, and accompanied by
      excommunication. Hence: Denunciation of anything as
      accursed.
      [1913 Webster]

            [They] denounce anathemas against unbelievers.
                                                  --Priestley.
      [1913 Webster]

   2. An imprecation; a curse; a malediction.
      [1913 Webster]

            Finally she fled to London followed by the anathemas
            of both [families].                   --Thackeray.
      [1913 Webster]

   3. Any person or thing anathematized, or cursed by
      ecclesiastical authority.
      [1913 Webster]

            The Jewish nation were an anathema destined to
            destruction. St. Paul . . . says he could wish, to
            save them from it, to become an anathema, and be
            destroyed himself.                    --Locke.
      [1913 Webster]

   Anathema Maranatha(see --1 Cor. xvi. 22), an expression
      commonly considered as a highly intensified form of
      anathema. Maran atha is now considered as a separate
      sentence, meaning, "Our Lord cometh."
      [1913 Webster] Anathematic

WordNet (r) 3.0 (2006):

anathema
    n 1: a detested person; "he is an anathema to me" [syn:
         anathema, bete noire]
    2: a formal ecclesiastical curse accompanied by excommunication

Moby Thesaurus II by Grady Ward, 1.0:

51 Moby Thesaurus words for "anathema":
   abhorrence, abomination, antipathy, arraignment, aversion, ban,
   bete noire, blame, blasphemy, bugbear, castigation, censure,
   commination, condemnation, curse, damnation, decrial, denouncement,
   denunciation, detestation, evil eye, excommunication, excoriation,
   execration, flaying, fulmination, fustigation, hate, hex,
   impeachment, imprecation, indictment, leper, malediction, malison,
   malocchio, outcast, pariah, peeve, pet peeve, phobia, pillorying,
   proscription, reprehension, reprobation, reproof, skinning alive,
   stricture, thundering, untouchable, whammy



Easton's 1897 Bible Dictionary:

Anathema
   anything laid up or suspended; hence anything laid up in a
   temple or set apart as sacred. In this sense the form of the
   word is _anath(ee)ma_, once in plural used in the Greek New
   Testament, in Luke 21:5, where it is rendered "gifts." In the
   LXX. the form _anathema_ is generally used as the rendering of
   the Hebrew word _herem_, derived from a verb which means (1) to
   consecrate or devote; and (2) to exterminate. Any object so
   devoted to the Lord could not be redeemed (Num. 18:14; Lev.
   27:28, 29); and hence the idea of exterminating connected with
   the word. The Hebrew verb (haram) is frequently used of the
   extermination of idolatrous nations. It had a wide range of
   application. The _anathema_ or _herem_ was a person or thing
   irrevocably devoted to God (Lev. 27:21, 28); and "none devoted
   shall be ransomed. He shall surely be put to death" (27:29). The
   word therefore carried the idea of devoted to destruction (Num.
   21:2, 3; Josh. 6:17); and hence generally it meant a thing
   accursed. In Deut. 7:26 an idol is called a _herem_ =
   _anathema_, a thing accursed.

     In the New Testament this word always implies execration. In
   some cases an individual denounces an anathema on himself unless
   certain conditions are fulfilled (Acts 23:12, 14, 21). "To call
   Jesus accursed" [anathema] (1 Cor. 12:3) is to pronounce him
   execrated or accursed. If any one preached another gospel, the
   apostle says, "let him be accursed" (Gal. 1:8, 9); i.e., let his
   conduct in so doing be accounted accursed.

     In Rom. 9:3, the expression "accursed" (anathema) from Christ,
   i.e., excluded from fellowship or alliance with Christ, has
   occasioned much difficulty. The apostle here does not speak of
   his wish as a possible thing. It is simply a vehement expression
   of feeling, showing how strong was his desire for the salvation
   of his people.

     The anathema in 1 Cor. 16:22 denotes simply that they who love
   not the Lord are rightly objects of loathing and execration to
   all holy beings; they are guilty of a crime that merits the
   severest condemnation; they are exposed to the just sentence of
   "everlasting destruction from the presence of the Lord."


Hitchcock's Bible Names Dictionary (late 1800's):

Anathema, separated; set apart


Bouvier's Law Dictionary, Revised 6th Ed (1856):

ANATHEMA, eccl. law. A punishment by which a person is separate from, the
body of the church, and forbidden all intercourse with the faithful: it
differs from excommunication, which simply forbids the person
excommunicated, from going into the church and communicating with the
faithful. Gal. 1. 8, 9.