Incompetent

Not competent; wanting in adequate strength, power, capacity, means, qualifications, or the like; incapable; unable; inadequate; unfit.

Wanting the legal or constitutional qualifications; inadmissible; as, a person professedly wanting in religious belief is an incompetent witness in a court of law or equity; incompetent evidence.

Not lying within one's competency, capacity, or authorized power; not permissible.