名词

1. 消失;失踪
If you refer to someone's disappearance, you are referring to the fact that nobody knows where they have gone.

2. 丢失;被盗
If you refer to the disappearance of an object, you are referring to the fact that it has been lost or stolen.

3. (指人、事物或动物)渐渐消失，灭绝
The disappearance of a type of thing, person, or animal is a process in which it becomes less common and finally no longer exists.

1. the act of leaving secretly or without explanation

Synonym: disappearing

2. gradually ceasing to be visible

Synonym: fade

3. the event of passing out of sight

4. ceasing to exist

e.g. he regretted the disappearance of Greek from school curricula
what was responsible for the disappearance of the rainforest?
the disappearance of resistance at very low temperatures