Fetching details from the dictionary...

to be delighted; to be glad; to be pleased; to rejoice
to congratulate
to welcome (a proposal, advice, etc.); to take kindly to
to do with pleasure; to do gladly; to be happy (to do)
社員全員が新社長の就任を慶んで拍手した。
All the employees rejoiced at the new president's inauguration and applauded.
合格を心より慶び申し上げますと伝えた。
I sincerely congratulate you on passing.
皆で勝利を慶んだ思い出の夜でした。
It was a night when we all celebrated the victory.