Unskilled; lacking the degree of ability that would normally be expected. / Unable to make rational decisions; insane or otherwise cognitively impaired.

A person who is incompetent.

In an incompetent manner.

plural of incompetent

The quality of being incompetent.

Inability to perform; lack of competence; ineptitude.

The condition of being incompetent.

(obsolete) Outside of one's competence

Archaic form of incompatible.

Obsolete form of incompatibility.