noun
Polite form of 誕生会, used when referring to someone else's birthday party or in formal contexts. The honorific お adds politeness.
See also: 誕生会
来週、友達のお誕生会に招待されました。
I was invited to my friend's birthday party next week.
お誕生会の準備はもうできましたか。
Are the preparations for the birthday party ready yet?