The Collaborative International Dictionary of English v.0.48:

Chastise \Chas*tise"\ (ch[a^]s*t[imac]z"; ch[a^]s"t[imac]z), v.
   t. [imp. & p. p. Chastised (ch[a^]s*t[imac]zd"); p. pr. &
   vb. n. Chastising.] [OE. chastisen; chastien + ending -isen
   + modern -ise, -ize, L. -izare, Gr. -i`zein. See Chasten.]
   1. To inflict pain upon, by means of stripes, or in any other
      manner, for the purpose of punishment or reformation; to
      punish, as with stripes.
      [1913 Webster]

            How fine my master is! I am afraid
            He will chastise me.                  --Shak.
      [1913 Webster]

            I am glad to see the vanity or envy of the canting
            chemists thus discovered and chastised. --Boyle.
      [1913 Webster]

   2. To reduce to order or obedience; to correct or purify; to
      free from faults or excesses.
      [1913 Webster]

            The gay, social sense, by decency chastised.
                                                  --Thomson.

   3. To criticize (a person) strongly and directly in order to
      correct behavior.

   Syn: castigate, objurgate, chasten, correct, dress down.
        [PJC]

   Syn: See Chasten.
        [1913 Webster]

WordNet (r) 3.0 (2006):

chastise
    v 1: censure severely; "She chastised him for his insensitive
         remarks" [syn: chastise, castigate, objurgate,
         chasten, correct]

Moby Thesaurus II by Grady Ward, 1.0:

46 Moby Thesaurus words for "chastise":
   admonish, baste, beat, belabor, berate, birch, bring to account,
   bring to book, call to account, cane, castigate, censure, chasten,
   chide, correct, deal with, discipline, flog, have words with,
   inflict upon, lecture, masthead, objurgate, penalize, pillory,
   pummel, punish, rate, rebuke, reprehend, reprimand, reprove, scold,
   scourge, set down, set straight, settle with, spank,
   square accounts, straighten out, take down, take to task, thrash,
   upbraid, visit upon, whip