n. an anniversary of the day on which a person was born (or the celebration of it)
n. the date on which a person was born
n. 生日
1. I am planning a surprise party for my friend's birthday.
我正在为我朋友的生日计划一个惊喜派对。
2. She received many gifts on her birthday.
她在生日那天收到了很多礼物。
3. My birthday is in July, and I always celebrate it with my family.
我的生日在七月，我总是和家人一起庆祝。