from The American Heritage® Dictionary of the English Language, 4th Edition
- adj. Acting or done without or against one's will: an involuntary participant in what turned out to be an argument.
- adj. Not subject to control of the volition: gave an involuntary start. See Synonyms at spontaneous.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- adj. Without intention; unintentional.
- adj. Not voluntary or willing; contrary or opposed to explicit will or desire; unwilling.
from the GNU version of the Collaborative International Dictionary of English
- adj. Not having will or the power of choice.
- adj. Not under the influence or control of the will; not voluntary
- adj. Not proceeding from choice; done unwillingly; reluctant; compulsory.
from The Century Dictionary and Cyclopedia
- Not voluntary or willing; contrary or opposed to will or desire; unwilling; unintentional: as, involuntary submission; an involuntary listener.
- Not voluntary or willed; independent of volition or consenting action of the mind; without the agency of the will: as, involuntary muscular action; an involuntary groan.
from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
- adj. not subject to the control of the will
- adj. controlled by the autonomic nervous system; without conscious control
From in- + voluntary, from Late Latin involontarius, from in + volontarius. (Wiktionary)