The Collaborative International Dictionary of English v.0.48:

Chasten \Chas"ten\ (ch[=a]"s'n), v. t. [imp. & p. p. Chastened
   (-s'nd); p. pr. & vb. n. Chastening.] [OE. chastien, OF.
   Chastier, F. Ch?tier, fr. L. castigare to punish, chastise;
   castus pure + agere to lead, drive. See Chaste, Act, and
   cf. Castigate, Chastise.]
   1. To correct by punishment; to inflict pain upon the purpose
      of reclaiming; to discipline; as, to chasten a son with a
      rod.
      [1913 Webster]

            For whom the Lord loveth he chasteneth. --Heb. xii.
                                                  6.
      [1913 Webster]

   2. To purify from errors or faults; to refine.
      [1913 Webster]

            They [classics] chasten and enlarge the mind, and
            excite to noble actions.              --Layard.

   Syn: To chastise; punish; correct; discipline; castigate;
        afflict; subdue; purify.

   Usage: To Chasten, Punish, Chastise. To chasten is to
          subject to affliction or trouble, in order to produce
          a general change for the better in life or character.
          To punish is to inflict penalty for violation of law,
          disobedience to authority, or intentional wrongdoing.
          To chastise is to punish a particular offense, as with
          stripes, especially with the hope that suffering or
          disgrace may prevent a repetition of faults.
          [1913 Webster]

WordNet (r) 3.0 (2006):

chasten
    v 1: censure severely; "She chastised him for his insensitive
         remarks" [syn: chastise, castigate, objurgate,
         chasten, correct]
    2: restrain [syn: chasten, moderate, temper]
    3: correct by punishment or discipline [syn: tame, chasten,
       subdue]