unstable
adjective uk/ʌnˈsteɪ.bəl/ us/ʌnˈsteɪ.bəl/
不稳固的；不牢靠的；不安全的
not solid and firm and therefore not strong, safe, or likely to last
That chair looks unstable to me. 那把椅子在我看来有点儿不结实。
It is a poor and politically unstable society. 这是一个贫穷落后且政局不稳的社会。
Synonyms: shaky (WEAK)unsound (WEAK)
（情绪）反复无常的，不稳定的
An unstable person suffers from sudden and extreme changes in their mental and emotional state.
emotionally unstable 情绪上反复无常