1. 短暂地
Something that happens or is done briefly happens or is done for a very short period of time.
e.g. He smiled briefly...
他微微笑了笑。
e.g. Guerillas captured and briefly held an important provincial capital.
游击队攻占并短暂控制了一个重要首府。
2. 简要地;简单地
If you say or write something briefly, you use very few words or give very few details.
e.g. There are four basic alternatives; they are described briefly below.
有4个基本的选项,简述如下。
3. 简言之;总之
You can say briefly to indicate that you are about to say something in as few words as possible.
e.g. Briefly, no less than nine of our agents have passed information to us.
总而言之,至少有9名特工向我们传递了情报。