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


not voluntary; independent of one's will; not by one's own choice: an involuntary listener; involuntary servitude.
unintentional; unconscious: an involuntary gesture.
Physiology. acting independently of or done or occurring without volition: involuntary muscles.

Origin of involuntary

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

OTHER WORDS FROM involuntary

in·vol·un·tar·i·ly [in-vol-uhn-ter-uh-lee, -vol-uhn-tair-] /ɪnˈvɒl ənˌtɛr ə li, -ˌvɒl ənˈtɛər-/, adverbin·vol·un·tar·i·ness, noun

synonym study for involuntary

1, 3. See automatic. Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2020

Examples from the Web for involuntary

British Dictionary definitions for involuntary

/ (ɪnˈvɒləntərɪ, -trɪ) /


carried out without one's conscious wishes; not voluntary; unintentional
physiol (esp of a movement or muscle) performed or acting without conscious control

Derived forms of involuntary

involuntarily, adverbinvoluntariness, noun
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

Medical definitions for involuntary

[ ĭn-vŏlən-tĕr′ē ]


Not subject to control of the volition.
Acting or done without or against one's will.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.

Scientific definitions for involuntary

[ ĭn-vŏlən-tĕr′ē ]

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.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.