The Collaborative International Dictionary of English v.0.48:

Persecution \Per`se*cu"tion\, n. [F. pers['e]cution, L.
   persecutio.]
   1. The act or practice of persecuting; especially, the
      infliction of loss, pain, or death for adherence to a
      particular creed or mode of worship.
      [1913 Webster]

            Persecution produces no sincere conviction. --Paley.
      [1913 Webster]

   2. The state or condition of being persecuted. --Locke.
      [1913 Webster]

   3. A carrying on; prosecution. [Obs.]
      [1913 Webster]

WordNet (r) 3.0 (2006):

persecution
    n 1: the act of persecuting (especially on the basis of race or
         religion)

Moby Thesaurus II by Grady Ward, 1.0:

65 Moby Thesaurus words for "persecution":
   McCarthyism, abuse, affliction, aggravation, annoyance, bad news,
   bedevilment, bore, bother, botheration, bothersomeness, bullying,
   clawing, crashing bore, cruciation, crucifixion, devilment,
   difficulty, dogging, downer, drag, exasperation, harassing,
   harassment, harrying, headache, hectoring, hell, hell upon earth,
   holocaust, horror, hounding, ill-treatment, irritation, laceration,
   lancination, maltreatment, martyrdom, molestation, nightmare,
   nuisance, oppression, outrage, passion, pest, problem, punishment,
   purgatory, rack, red-baiting, subjugation, suppression, torment,
   tormenting, torture, trial, trouble, tyranny, vexation,
   vexatiousness, victimization, witch-hunt, witch-hunting, worriment,
   worry



Easton's 1897 Bible Dictionary:

Persecution
   The first great persecution for religious opinion of which we
   have any record was that which broke out against the worshippers
   of God among the Jews in the days of Ahab, when that king, at
   the instigation of his wife Jezebel, "a woman in whom, with the
   reckless and licentious habits of an Oriental queen, were united
   the fiercest and sternest qualities inherent in the old Semitic
   race", sought in the most relentless manner to extirpate the
   worship of Jehovah and substitute in its place the worship of
   Ashtoreth and Baal. Ahab's example in this respect was followed
   by Manasseh, who "shed innocent blood very much, till he had
   filled Jerusalem from one end to another" (2 Kings 21:16; comp.
   24:4). In all ages, in one form or another, the people of God
   have had to suffer persecution. In its earliest history the
   Christian church passed through many bloody persecutions. Of
   subsequent centuries in our own and in other lands the same sad
   record may be made.

     Christians are forbidden to seek the propagation of the gospel
   by force (Matt. 7:1; Luke 9:54-56; Rom. 14:4; James 4:11, 12).
   The words of Ps. 7:13, "He ordaineth his arrows against the
   persecutors," ought rather to be, as in the Revised Version, "He
   maketh his arrows fiery [shafts]."