involuntary

Adjective

• controlled by the autonomic nervous system; without conscious control
  • involuntary muscles
    
  • gave an involuntary start
    

• 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
    

Related words

• Synonyms: 
  nonvoluntary , unvoluntary