definition of
voluntary

[1] #1 voluntary a. of your own free will or design; done by choice; not forced or compelled; "man is a voluntary agent"; "participation was voluntary"; "voluntary manslaughter"; "voluntary generosity in times of disaster"; "voluntary social workers"; "a voluntary confession. wn

[2] #2 voluntary n. [volunteer, military volunteer] (military) a person who freely enlists for service. wn

[3] #3 voluntary n. composition (often improvised) for a solo instrument (especially solo organ) and not a regular part of a religious service or musical performance. wn

[4] #4 voluntary a. controlled by individual volition; "voluntary motions"; "voluntary muscles". wn