This is the 3075th most frequent Japanese word.
不安定
Unstable; insecure.
The term '不安定' is used here to describe the physical instability of the bridge.
この橋は不安定で、通行するには危険です。
This bridge is unstable and dangerous to cross.
In this sentence, '不安定' characterizes the emotional or mental state of a person.
彼の気分は最近、不安定になっているようです。
His mood seems to have become unstable lately.
The word '不安定' here refers to the uncertain or fluctuating state of the economy.