'Involuntary' definitions:

Definition of 'involuntary'

From: WordNet
adjective
Not subject to the control of the will; "involuntary manslaughter"; "involuntary servitude"; "an involuntary shudder"; "It (becoming a hero) was involuntary. They sank my boat"- John F.Kennedy [syn: involuntary, nonvoluntary, unvoluntary] [ant: voluntary]
adjective
Controlled by the autonomic nervous system; without conscious control; "involuntary muscles"; "gave an involuntary start" [ant: voluntary]

Definition of 'Involuntary'

From: GCIDE
  • Involuntary \In*vol"un*ta*ry\, a. [L. involuntarius. See In- not, and Voluntary.] [1913 Webster]
  • 1. Not having will or the power of choice. [1913 Webster]
  • 2. Not under the influence or control of the will; not voluntary; as, the involuntary movements of the body; involuntary muscle fibers. [1913 Webster]
  • 3. Not proceeding from choice; done unwillingly; reluctant; compulsory; as, involuntary submission. Involute