unstable

An unstable situation or system is one that's prone to change or collapse. Think of a wobbly chair – it might fall over at any moment.

When we talk about things being unstable, we usually mean they can't stay the same for long. For example, an economy might be unstable if people are losing their jobs and can't afford basic necessities. This means that the economic situation is unpredictable and could change suddenly. If someone's personal life is unstable, it might mean they're dealing with a lot of stress or drama, like a messy breakup or financial troubles.