involuntary

adjective

in·​vol·​un·​tary (ˌ)in-ˈvä-lən-ˌter-ē 

-ˌte-rē

1

: done contrary to or without choice

2

: compulsory

3

: not subject to control of the will : reflex

involuntarily

(ˌ)in-ˌvä-lən-ˈter-ə-lē 

-ˈte-rə-

adverb

involuntariness

(ˌ)in-ˈvä-lən-ˌter-ē-nəs 

-ˌte-rē-

noun

Synonyms of involuntary

• accidental
• spontaneous
• unwilling
• unintentional
• forced
• coerced

Examples of involuntary in a Sentence

Breathing and circulation are involuntary processes.

When the door burst open, she let out an involuntary shriek.

The lawyer argued that the client's confession was involuntary.

Recent Examples on the Web

The company’s campaign directs people experiencing involuntary movements to their dedicated website and encourages them to consult healthcare providers. — Joshua Hong, Fortune, 29 July 2026

While hearing is involuntary, effective listening is actually a conscious choice—a cognitively demanding one. — Julia Korn, Forbes.com, 27 July 2026

Mayor Eric Adams prioritized eliminating encampments by pursuing an aggressive strategy of criminalization and encampment sweeps led by the NYPD, and expanded use of involuntary hospitalizations. — Dave Giffen, New York Daily News, 26 July 2026

Yet for some thinkers today the involuntary dispersion of the Jews (galut or golah) is articulated as being inherently different from the voluntary exile of the Jews (diaspora or tfutsot). — Literary Hub, 24 July 2026

Word History

Etymology

Middle English involuntari, from Late Latin involuntarius, from Latin in- + voluntarius voluntary

First Known Use

15th century, in the meaning defined at sense 1

Phrases Containing involuntary

• involuntary manslaughter
• involuntary muscle

Rhymes for involuntary

• accretionary
• apothecary
• bicentenary
• certiorari
• concessionary
• concretionary
• confectionary
• confectionery
• constabulary
• contemporary
• deflationary
• depositary

Kids Definition

involuntary

adjective

in·​vol·​un·​tary (ˈ)in-ˈväl-ən-ˌter-ē 

1

: not made or done willingly or from choice : unwilling

2

: being enforced or required : mandatory

3

: not normally under the control of the will

an involuntary response to a stimulus

involuntarily

(ˌ)in-ˌväl-ən-ˈter-ə-lē 

adverb

Medical Definition

involuntary

adjective

in·​vol·​un·​tary (ˈ)in-ˈväl-ən-ˌter-ē 

: not subject to control of the will : reflex

involuntary contractions

Legal Definition

involuntary

adjective

in·​vol·​un·​tary in-ˈvä-lən-ˌter-ē 

: done, made, or initiated contrary to or without one's choice

an involuntary confession

an involuntary lien

an involuntary plaintiff joined in the action

involuntarily adverb