1. (

• involuntary ,
• nonvoluntary ,
• unvoluntary

) 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 ;

2. (

• involuntary ,

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