incapable

American Heritage® Dictionary of the English Language, Fourth Edition

1. adj. Lacking the necessary ability, capacity, or power: incapable of carrying a tune; incapable of love.
2. adj. Unable to perform adequately; incompetent: an incapable administrator.
3. adj. Usage Problem Not susceptible to action or treatment: a unique feat, incapable of duplication. See Usage Note at able.
4. adj. Law Lacking legal qualifications or requirements; ineligible.

Century Dictionary and Cyclopedia

1. Not capable. Lacking in capacity, ability, or fitness; inefficient; incompetent; inadequate.
2. Lacking sufficient capacity or capaciousness; insufficient, unfit, or unqualified: in this and the succeeding uses commonly followed by of.
3. Not capable of receiving or admitting; not susceptible: as, his lot is incapable of amelioration.
4. Not capable of understanding or comprehending; wanting appreciation; unconscious.
5. Not capable legally; unqualified; disqualified by law; wanting legal warrant or capacity.
6. Synonyms Incapable, Unable. Incapable properly denotes a want of passive power, the power of receiving, and is applicable particularly to the mind, or said of something inanimate: as, a body once dead is incapable of restoration to life. The word often applies to moral inability: as, he is quite incapable of doing a thing so base; or otherwise it approaches essentially the more active meanings of unable. Unable denotes the want of active power or power of performing, being applicable to the body or to the mind: we could not say that Achilles was unable to be wounded, but we could say that Achilles was incapable of a wound. In law capable and incapable refer more frequently to legal qualification, able and unable to physical facility or hindrance: as, a man may not be legally incapable of doing an act, yet from circumstances be practically unable to do it.
7. n. One who lacks mental or physical capacity, either general or special.

Wiktionary

1. adj. Not capable (of doing something); unable.
2. n. dated One who is morally or mentally weak or inefficient; an imbecile; a simpleton.

GNU Webster's 1913

1. adj. Lacking in ability or qualification for the purpose or end in view; not large enough to contain or hold; deficient in physical strength, mental or moral power, etc.; not capable
2. adj. Not capable of being brought to do or perform, because morally strong or well disposed; -- used with reference to some evil.
3. adj. Not in a state to receive; not receptive; not susceptible; not able to admit
4. adj. (Law) Unqualified or disqualified, in a legal sense
5. adj. (Mil.) As a term of disgrace, sometimes annexed to a sentence when an officer has been cashiered and rendered incapable of serving his country.
6. n. One who is morally or mentally weak or inefficient; an imbecile; a simpleton.

WordNet 3.0

1. adj. (followed by `of') not having the temperament or inclination for
2. adj. not meeting requirements
3. adj. not being susceptible to or admitting of something (usually followed by `of')
4. adj. (followed by `of') lacking capacity or ability