ability:
incapacity,
ineptness,
incapability,
inability,
incompetence.
noun:
disablement,
incompetency,
defectiveness,
dulness,
inefficaciousness,
imbecility,
inefficacy,
ineptitude,
ineffectualness,
weakness,
helplessness,
inaptitude,
inefficiency,
stupidity,
maladroitness,
ineptness,
feebleness,
inadequateness,
impairment,
debilitation,
inadequacy,
paralysis,
Incapacitation,
disability,
awkwardness,
deficiency,
uselessness,
powerlessness,
incapableness,
ineffectiveness,
impotence,
ineffectuality.