from The American Heritage® Dictionary of the English Language, 4th Edition
- adj. Lacking the necessary power, authority, or means; not able; incapable: unable to get to town without a car.
- adj. Lacking mental or physical capability or efficiency; incompetent: unable to walk.
- adj. Usage Problem Not susceptible to action or treatment: a project unable to be financed with government funds. See Usage Note at able.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- adj. Not able; lacking a certain ability.
from the GNU version of the Collaborative International Dictionary of English
- adj. 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.
from The Century Dictionary and Cyclopedia
- Not able.
- Lacking in ability; incapable.
- Weak; helpless; useless.
from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
- adj. (usually followed by `to') not having the necessary means or skill or know-how
- adj. lacking in power or forcefulness
- adj. (usually followed by `to') lacking necessary physical or mental ability
un- + able (Wiktionary)