D defs.my
Entry 1 sense Webster, 1913

Unable

/ən-āb'-əl/ · Un·a·ble · IPA /ʌnˈeɪbl̩/
01 a. Not able; not having sufficient strength, means, knowledge, skill, or the like; impotent; weak; helpless; incapable; -- now usually followe…
  1. 1.
    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.
    “Sapless age and weak unable limbs.” Shak.