Celebration, Congratulatory Gift
noun, verbal noun
This is the noun version of the kanji celebrate, so it means celebration! お祝い is also used to mean a congratulatory gift itself.
おいわい
Since this word consists of a kanji with hiragana attached, you can bet that it will use the kun'yomi reading. You learned this reading already so you should be able to read it!
おばあちゃんから大学の入学のお祝いにスマホをもらった。
I got a smartphone from my grandma as a congratulatory gift for starting university.
新しい仕事見つかったの？今度お祝いしなきゃね。
Oh, you've found a new job? We'll have to celebrate sometime.
せっかくのお祝いの席なのに、税金の話ばっかりしないでよ！
Don't keep talking about taxes when you're at a celebration!
引っ越しのお祝いを渡さなくちゃいけないわね。
We have to bring a moving gift.
お祝いの言葉を伝える時に、お祝いっぽい曲をかけようよ。
When conveying words of celebration, let's play a celebratory song.