1 likely to fall down or move; not firmly fixed 容易倒塌或移动的;不稳固的
2 likely to change or fail 易变的;不稳定的:
a period of unstable government政府不稳定时期
3 (used about a person's moods or behaviour) likely to change suddenly or often (指人的情绪或行为)容易波动的,反复无常的
[OPP] stable 反义词为stable☞noun instability 名词为instability