inability Meaning, Definition & Usage

  1. noun lack of ability (especially mental ability) to do something
  2. noun lacking the power to perform
    unfitness.

WordNet

In`a*bil"i*ty noun
Etymology
Pref. in- not + ability: cf. F. inhabileté. See Able, and cf. Unable.
Definitions
  1. The quality or state of being unable; lack of ability; want of sufficient power, strength, resources, or capacity.
    It is not from an inability to discover what they ought to do, that men err in practice. Blair.
    Syn. -- Impotence; incapacity; incompetence; weakness; powerlessness; incapability. See Disability.

Webster 1913