✔ 最佳答案
It would depend on the usage and meaning. It could be:
... emergency (a noun, such as):
In case of emergency, call 999.
... urgency (a noun, such as):
Please circulate the reminder in your department in view of the urgency of the matter.
... urgently (an adverb, such as):
Where have you been? The boss is urgently looking for you.
... and many others such as critical, crucial, pressing, etc that can be used in one form or another to mean 緊急.
If you can provide more background of what you wish to describe, it would definitely help us to help you.
Hope the above helps.