unstablePronunciation: /ʌnˈsteɪb(ə)l/Translate unstable | into French | into German | into Italian | into Spanish Definition of unstable adjective (unstabler, unstablest) likely to give way; not stable:the unstable cliff tops likely to change or fail; not firmly established:an unstable government prone to psychiatric problems or sudden changes of mood:he was mentally unstableDerivatives unstableness noun unstably adverb unstable in other Oxford dictionaries Definition of unstable in the US English dictionary
