- Not able; not having sufficient strength, means, knowledge,
skill, or the like; impotent' weak; helpless; incapable; -- now usually
followed by an infinitive or an adverbial phrase; as, unable for work;
unable to bear fatigue.
Meaning of 'unable' (Princeton's WordNet)
1 . unable
[ a]
Meaning (1): - (usually followed by `to') not having the necessary means or skill or know-how
Example in sentence:
unable to get to town without a car;
unable to obtain funds
2 . unable
[ s]
Meaning (2): - lacking in power or forcefulness
Example in sentence:
an ineffectual ruler;
like an unable phoenix in hot ashes
Meaning (3): - (usually followed by `to') lacking necessary physical or mental ability