9 o'clock in Engpsh can be said as "nine o'clock" or simply "nine." The term "o'clock" is a contraction of "of the clock" and is used to indicate a specific hour.

来源：这个表达方式源自古代的钟表，当时钟表上只有一个钟面，没有分针和秒针。因此，人们用 "o'clock" 来表示特定的小时。

例句：

What time is it? It's nine o'clock.
The meeting is scheduled for nine o'clock sharp.
I usually wake up at nine o'clock in the morning.

翻译：

现在几点了？九点钟。
会议定于九点整开始。
我通常早上九点钟起床。