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

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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

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involuntary Scientific  

/ ĭn-vŏl′ən-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.

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Synonym Usage

See automatic.

Other Word Forms

• involuntarily
  adverb
• involuntariness
  noun

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.

Example Sentences

He had just been sent away on an involuntary midseason vacation, and he wanted Chaney to come to the lobby and help him hail a taxi.

From The Wall Street Journal • May 8, 2026

While Tourette syndrome has many complex symptoms, “I Swear” focuses largely on coprolalia, a symptom affecting approximately 10% of individuals with Tourette’s and manifests in the involuntary use of obscene language.

From Salon • Apr. 26, 2026

It’s 1983 in Galashiels, Scotland, and his involuntary movements and outbursts are seen as misbehavior, teenage rebellion, and treated in kind.

From Los Angeles Times • Apr. 24, 2026

As she attempted to lift weights in the gym, involuntary tremors would set her limbs shaking.

From BBC • Apr. 15, 2026

An involuntary, wordless shout left him as he took a few hurried steps along the drive, faltered, ran on, then stopped again, knowing that pursuit was pointless.

From "Atonement" by Ian McEwan

Related Words

• compulsory
• forced
• spontaneous
• uncontrolled
• unintentional