a.[Z]

1. 瞬间的，实时的
   The reaction of the audience was instantaneous.

   观众即刻有了反应。

2. 猝然的，猝发的
   She accidentally swallowed the poison and death was instantaneous.

   她无意中吞下毒药，猝然死去。

3. 【物】瞬时的，实时的

adj.

1. occurring or done instantly.
2. Physics  existing or measured at a particular instant.