n. Want of competent power, strength, or physical or mental ability: weakness; incapacity; impotence: as, disability arising from infirmity; a blind person labors under great disability.n. Specifically Want of competent means or instruments.n. Want of legal capacity or qualification; legal incapacity; incapacity to do an act with legal effect.n. Synonyms Disability. Inability, incompetence, incapacity, disqualification, unfitness. Disability implies deprivation or loss of power; inability indicates rather inherent want of power. One declines an office from inability to discharge its duties, but is not elected to it because of some external disability disqualifying him for being chosen.