incompetent

adjective

in·​com·​pe·​tent (ˌ)in-ˈkäm-pə-tənt 

1

a

: lacking the qualities needed for effective action : lacking necessary ability or skills

b

: unable to function properly

incompetent heart valves

2

: not legally qualified

After hearing psychiatrist … witnesses … the court found Edwards incompetent to stand trial …

—Indiana v. Edwards, 554 U.S. 164 (2008)

3

: inadequate to or unsuitable for a particular purpose

incompetent noun

incompetently adverb

Synonyms of incompetent

• unfit
• unfitted
• incapable

Examples of incompetent in a Sentence

He is too incompetent to be trusted with such an important responsibility.

The patient is mentally incompetent.

The defendant was declared incompetent to stand trial.

Recent Examples on the Web

Milwaukee County Judge Laura Crivello ordered Spors to be committed for mental health treatment after reviewing a report from a psychiatrist that found Spors is incompetent but likely to regain competency. —Eva Wen, jsonline.com, 21 Nov. 2025

It was intended to prioritize mental health care for those found incompetent to stand trial. —Gabriela Vidal, CBS News, 18 Nov. 2025

The man accused of fatally shooting longtime American Idol music supervisor Robin Kaye and her musician husband, Thomas Deluca, was declared incompetent to stand trial at a morning hearing on Thursday. —Nancy Dillon, Rolling Stone, 13 Nov. 2025

Under California law, people who are found incompetent to stand trial must be sent to a state hospital or secure mental health care facility. —Nathaniel Percy, Oc Register, 7 Nov. 2025

Word History

Etymology

Middle French incompétent, from in- + compétent competent

First Known Use

1595, in the meaning defined at sense 2

Rhymes for incompetent

• competent
• immunocompetent

Kids Definition

incompetent

1 of 2 adjective

in·​com·​pe·​tent

(ˈ)in-ˈkäm-pət-ənt

1

: not legally qualified

2

: lacking qualities (as knowledge, skill, or ability) needed to do something well

an incompetent writer

incompetently adverb

incompetent

2 of 2 noun

: an incompetent person

Medical Definition

incompetent

adjective

in·​com·​pe·​tent (ˈ)in-ˈkäm-pət-ənt 

1

: not legally qualified

especially : incapable due to a mental or physical condition

2

: unable to function properly

incompetent heart valves

incompetently adverb

Legal Definition

incompetent

1 of 2 adjective

in·​com·​pe·​tent in-ˈkäm-pə-tənt 

1

: not legally qualified: as

a

: lacking legal capacity (as because of age or mental deficiency)

b

: incapable due to mental or physical condition compare competent

c

: lacking authority, power, or qualifications required by law

an incompetent court

incompetent evidence

2

: unable or failing to perform adequately

fired for being incompetent

an incompetent attorney

compare ineffective assistance of counsel

incompetent

2 of 2 noun

: a person who is incompetent compare interdict