unconscious

1 of 2

adjective

un·​con·​scious ˌən-ˈkän(t)-shəs 

1

a

: having lost consciousness

was unconscious for three days

b(1)

: not marked by conscious thought, sensation, or feeling

unconscious motivation

(2)

: of or relating to the unconscious

c

: not possessing mind or consciousness

unconscious matter

2

a

: not knowing or perceiving : not aware

b

: free from self-awareness

3

: not consciously held or deliberately planned or carried out

an unconscious bias

unconsciously adverb

unconsciousness noun

unconscious

2 of 2

noun

: the part of mental life that does not ordinarily enter the individual's awareness yet may influence behavior and perception or be revealed (as in slips of the tongue or in dreams)

Synonyms

Adjective

• cold
• senseless

Examples of unconscious in a Sentence

Adjective

He was knocked unconscious by a fall.

She was unconscious for three days after the accident.

Recent Examples on the Web

Adjective

In some cases, AI feedback forced Martinez to reflect on how unconscious bias may have shaped his original assessment. —Beatrice Nolan, Fortune, 8 July 2025

Used responsibly, these systems can offer clearer benchmarks and reduce unconscious bias. —Andrew Fennell, Forbes.com, 7 July 2025

Noun

In 2014, four Air Force servicemen were killed after a flock of Canadian geese reportedly flew through their helicopter’s windshield, knocking the pilot and copilot unconscious. —Mack Degeurin, Popular Science, 10 July 2025

The 1968 revolution was a revelation of the French unconscious. —Callum McLennan, Variety, 17 Feb. 2025

Word History

First Known Use

Adjective

1712, in the meaning defined at sense 2a

Noun

circa 1912, in the meaning defined above

Phrases Containing unconscious

• collective unconscious

Rhymes for unconscious

• conscious
• preconscious
• subconscious

Kids Definition

unconscious

1 of 2 adjective

un·​con·​scious ˌən-ˈkän-chəs 

ˈən-

1

: not aware

unconscious of having made a mistake

2

: having lost consciousness

knocked unconscious by a fall

3

: not realized : not consciously done

an unconscious mistake

unconscious humor

unconsciously adverb

unconsciousness noun

unconscious

2 of 2 noun

: the part of one's mental life of which one is not aware but which may influence behavior

Medical Definition

unconscious

1 of 2 adjective

un·​con·​scious ˌən-ˈkän-chəs 

1

: not marked by conscious thought, sensation, or feeling

unconscious motivation

2

: of or relating to the unconscious

3

: having lost consciousness

was unconscious for three days

unconsciously adverb

unconsciousness noun

unconscious

2 of 2 noun

: the part of mental life that is not ordinarily integrated or available to consciousness yet may be manifested as a motive force in overt behavior (as in neurosis) and is often revealed (as through dreams, slips of the tongue, or dissociated acts) compare subconscious