[adjective] - unable to do somethingHe seems incapable of walking past a music shop without going in and buying another CD.She's incapable of (doing) such a dreadful thing.She's a brilliant mathematician, but as a lecturer she's totally incapable.
INCAPABLE
Meaning of INCAPABLE in English
Cambridge English vocab. Кембриджский английский словарь. 2012