unable

adjective

1. (usually followed by `to') not having the necessary means or skill or know-how

- unable to get to town without a car

- unable to obtain funds

2. (usually followed by `to') lacking necessary physical or mental ability

- dyslexics are unable to learn to read adequately

- the sun was unable to melt enough snow

Similar word(s): incapable

3. lacking in power or forcefulness

- like an unable phoenix in hot ashes

Similar word(s): impotent, ineffective, ineffectual