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

Messy data creates an incompetent digital workforce. —Yasmeen Ahmad, Fortune, 21 Jan. 2026

The series sees paper company workers mixing not-so-serious business and personal affairs while operating under an incompetent but endearing boss (played to perfection by Steve Carell). —Chris Snellgrove, Entertainment Weekly, 17 Jan. 2026

Every position eventually fills with someone incompetent at that level. —Vibhas Ratanjee, Forbes.com, 17 Jan. 2026

Police later charged the suspect with endangering the welfare of an incompetent or physically disabled person, a class E felony, and endangering the welfare of a child. —Brian Niemietz, New York Daily News, 16 Jan. 2026

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