congratulation

con·grat·u·la·tion /kənˌgræʧəˈleɪʃən, kənˌgræʤəˈleɪʃən/ noun, pl -tions
1 congratulations [plural]
a : a message telling someone that you are happy because of his or her success or good luck : words that congratulate someone
• Let me offer you my congratulations for/on being elected.
• Please send her my congratulations.
b
- used to tell someone that you are happy because of his or her success or good luck
• “I got promoted!” “Congratulations!”
- often + on
• Congratulations on your promotion!
• Congratulations on a job well done.
2 formal : the act of telling someone that you are happy because of his or her success or good luck : the act of congratulating someone

[plural]

• I sent her a letter/message of congratulations.

[noncount]

• a letter/message of congratulation