Wordnet 3.0
ADJECTIVE (1)
1. 
 not subject to the control of the will; 
- Example: "involuntary manslaughter"- Example: "involuntary servitude"- Example: "an involuntary shudder"- Example: "It (becoming a hero) was involuntary. They sank my boat"- John F.Kennedy[syn: involuntary, nonvoluntary, unvoluntary]
The Collaborative International Dictionary of English v.0.48:
Unvoluntary \Un*vol"un*ta*ry\, a.
   Involuntary. [Obs.] --Fuller.
   [1913 Webster]
WordNet (r) 3.0 (2006):
unvoluntary
    adj 1: 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]