Source : Webster's Revised Unabridged Dictionary (1913)

Congratulation \Con*grat`u*la"tion\, n. [L. congratulatio: cf.
   F. congratulation.]
   The act of congratulating; an expression of sympathetic
   pleasure.

         With infinite congratulations for our safe arrival.
                                                  --Dr. J.
                                                  Scott.

Source : WordNet®

congratulation
     n 1: the act of acknowledging that someone has an occasion for
          celebration [syn: {felicitation}]
     2: (usually plural) an expression of pleasure at the success or
        good fortune of another; "I sent them my sincere
        congratulations on their marriage" [syn: {felicitation}]