Source : Webster's Revised Unabridged Dictionary (1913)

Gratulate \Grat"u*late\, v. t. [imp. & p. p. {Grqatulated}; p.
   pr. & vb. n. {Gratulating}.] [L. gratulatus, p. p. of
   gratulari to congratulate, fr. gratus pleasing, agreeable.
   See {Grate}, a.]
   To salute with declaration of joy; to congratulate. [R.]
   --Shak.