The Collaborative International Dictionary of English v.0.48:

Castigation \Cas`ti*ga"tion\, n. [L. catigatio.]
   [1913 Webster]
   1. Corrective punishment; chastisement; reproof; pungent
      criticism.
      [1913 Webster]

            The keenest castigation of her slanderers. --W.
                                                  Irving.
      [1913 Webster]

   2. Emendation; correction. [Obs.]
      [1913 Webster]

WordNet (r) 3.0 (2006):

castigation
    n 1: a severe scolding [syn: castigation, earful, bawling
         out, chewing out, upbraiding, going-over, dressing
         down]
    2: verbal punishment [syn: castigation, chastisement]