(1):

(a.) 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.

(2):

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

(3):

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