The Collaborative International Dictionary of English v.0.48:

Castigate \Cas"ti*gate\, v. t. [imp. & p. p. Castigated; p.
   pr. & vb. n. Castigating.] [L. castigatus, p. p. of
   castigare to correct, punish; castus pure, chaste + agere to
   move, drive. See Caste, and cf. Chasten.]
   1. To punish by stripes; to chastise by blows; to chasten;
      also, to chastise verbally; to reprove; to criticise
      severely.
      [1913 Webster]

   2. To emend; to correct. [Obs.]
      [1913 Webster]

WordNet (r) 3.0 (2006):

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