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involuntary

American  
[in-vol-uhn-ter-ee] / ɪnˈvɒl ənˌtɛr i /

adjective

  1. not voluntary; independent of one's will; not by one's own choice.

    an involuntary listener; involuntary servitude.

  2. unintentional; unconscious.

    an involuntary gesture.

    Synonyms:
    instinctive
    Antonyms:
    intentional
  3. Physiology. acting independently of or done or occurring without volition.

    involuntary muscles.

    Synonyms:
    uncontrolled, reflex

involuntary British  
/ -trɪ, ɪnˈvɒləntərɪ /

adjective

  1. carried out without one's conscious wishes; not voluntary; unintentional

  2. physiol (esp of a movement or muscle) performed or acting without conscious control

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

involuntary Scientific  
/ ĭn-vŏlən-tĕr′ē /
  1. Not under conscious control. Most of the biological processes in animals that are vital to life, such as contraction of the heart, blood flow, breathing, and digestion, are involuntary and controlled by the autonomic nervous system.


Synonym Usage

See automatic.

Other Word Forms

Etymology

Origin of involuntary

From the Late Latin word involuntārius, dating back to 1525–35. See in- 3, voluntary

Explanation

Involuntary describes a reflex or action done without conscious control or will — like a blink, a sneeze, a yawn, or “the giggles.” If you volunteered to do it, it’s voluntary. If you didn’t volunteer, but you find yourself doing it anyway, it’s involuntary. This can go for the involuntary hiccups you wrestle with on your blind date, as well as the involuntary task you do at your manager’s insistence. Involuntary gets a lot of blame, but something that is involuntary is not necessarily bad: Breathing is involuntary, but you would probably do it anyway if given the choice.

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Vocabulary lists containing involuntary

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

"Involuntary installations have been a last – but necessary – resort for cases where repeated attempts to address debt with the customer through other means have been unsuccessful," she said.

From BBC • May 27, 2025

Involuntary treatment is claimed to be necessary because people would not enter therapy voluntarily.

From Salon • Nov. 17, 2024

Involuntary servitude, however, is still in the Constitution.

From Los Angeles Times • Nov. 17, 2024

Involuntary manslaughter carries a felony sentence of up to 18 months in prison and a $5,000 fine.

From Seattle Times • Mar. 13, 2024

Involuntary movements without loss of consciousness constitute the disorder commonly known as St. Vitus's Dance.

From The Mother's Manual of Children's Diseases by West, Charles

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