The Collaborative International Dictionary of English v.0.48:
Congratulatory \Con*grat"u*la*to*ry\, a. Expressive of sympathetic joy; as, a congratulatory letter. [1913 Webster]WordNet (r) 3.0 (2006):
congratulatory adj 1: expressive of sympathetic pleasure or joy on account of someone's success or good fortune; "a congratulatory telegram"; "the usual congratulatory crowd was conspicuously absent"; "a gratulatory address" [syn: congratulatory, gratulatory]