Word parts un- + able Pronunciation IPA (key): /ʌnˈeɪbəl/ Audio (US)(file) Adjective Positive unable Comparative none Superlative none When sosmeone or something is unable to do something, it cannot be done; it is not able to do it. Antonym: able I am unable to climb that mountain because I am too weak.Wikiwand - on Seamless Wikipedia browsing. On steroids.Remove ads