1. 瞬息;顷刻;刹那
    An instant is an extremely short period of time.

    e.g. For an instant, Catherine was tempted to flee...
           有那么一会儿,凯瑟琳很想逃跑。
    e.g. The pain disappeared in an instant.
           疼痛立刻就消失了。

2. (某一)时刻
    If you say that something happens at a particular instant, you mean that it happens at exactly the time you have been referring to, and you are usually suggesting that it happens quickly or immediately.

    e.g. At that instant the museum was plunged into total darkness...
           就在那时,博物馆陷入了一片漆黑。
    e.g. In the same instant he flung open the car door.
           与此同时,他猛地推开了车门。

3. 一…(就)
    To do something the instant something else happens means to do it immediately.

instant的反义词

    e.g. I had bolted the door the instant I had seen the bat.
           我一看到蝙蝠就把门闩上了。

4. 立即的;即刻的
    You use instant to describe something that happens immediately.

instant的解释

    e.g. Mr Porter's book was an instant hit...
           波特先生的书一经推出便大受欢迎。
    e.g. He had taken an instant dislike to Mortlake.
           他一到莫特莱克就觉得不喜欢这个地方。

5. (食品)已配制好的，调制快速方便的，速溶的
    Instant food is food that you can prepare very quickly, for example by just adding water.

    e.g. ...instant coffee.
           速溶咖啡