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

• 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

After awarding the voluntary furlough, management will proceed with involuntary furloughs in inverse order of system seniority up to the 1,800 number, in accordance with flight attendant contracts, the union said. —Michelle Del Rey, USA Today, 23 Sep. 2025

Doctors placed him on an involuntary psychiatric hold. —Dhruv Khullar, New Yorker, 22 Sep. 2025

Union Pacific has committed that these employees will not face involuntary furloughs because of the merger, the union said. —Glenn Taylor, Sourcing Journal, 22 Sep. 2025

Future studies should test voluntary vs involuntary retirement and longer follow-up periods. —New Atlas, 20 Sep. 2025

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