Unable

unable
    adj 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" [ant: {able}]
    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"
    3: lacking in power or forcefulness; "an ineffectual ruler";
       "like an unable phoenix in hot ashes" [syn: {ineffective},
       {ineffectual}, {unable}]
    

Unable \Un*a"ble\, a.
   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.
   [1913 Webster]

         Sapless age and weak unable limbs.       --Shak.
   [1913 Webster]
    

25 Moby Thesaurus words for "unable":
      ill-qualified, impotent, inadequate, incapable, incapable of,
      incompetent, ineffective, ineffectual, inefficient, inept,
      inferior, maladjusted, not equal to, not up to, powerless,
      unable to, unadapted, unadjusted, unendowed, unequipped, unfit,
      unfitted, ungifted, unqualified, untalented