[ in-vol-uhn-ter-ee ]
/ ɪnˈvɒl ənˌtɛr i /
Save This Word!
See synonyms for: involuntary / involuntarily on Thesaurus.com

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.
Apostrophes can be tricky; prove you know the difference between "it’s" and "its" in this crafty quiz!
Question 1 of 8
On the farm, the feed for chicks is significantly different from the roosters’; ______ not even comparable.

Origin of involuntary

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

synonym study for involuntary

1, 3. See automatic.

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
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2022

How to use involuntary in a sentence

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.