con‧grat‧u‧la‧tion S3 [uncountable]
used when you want to congratulate someone:
'I've just passed my driving test!' 'Congratulations!'
Congratulations on a superb performance!
words saying you are happy that someone has achieved something:
Give Oscar my congratulations.
when you tell someone that you are happy because they have achieved something or because something nice has happened to them:
letters of congratulation