unstable

1. ADJ You can describe something as unstable if it is likely to change suddenly, especially if this creates difficulty or danger. 不穩定的

The situation is unstable and potentially dangerous. 情況不穩定，可能有危險。

2. ADJ Unstable objects are likely to move or fall. 不牢固的

Both clay and sandstone are unstable rock formations. 黏土和砂巖都是不堅固的巖石搆造。

3. ADJ If people are unstable, their emotions and behaviour keep changing because their minds are disturbed or upset. 多變的 (情緒或行爲)

He was emotionally unstable. 他情緒多變。