voluntary

nouns

(military) a person who freely enlists for service
military volunteer, voluntary, volunteer
is derived from
volunteer
composition (often improvised) for a solo instrument (especially solo organ) and not a regular part of a religious service or musical performance
voluntary
is a type of (narrower)
a musical composition for one voice or instrument (with or without accompaniment)
solo

adjectives

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"
voluntary
antonym
involuntary
is similar to
done by design
"the insult was intentional"; "willful disobedience"
wilful, willful
is similar to
done of your own accord
"a freewill offering"
freewill
is similar to
voluntarily assumed or endured
"self-imposed exile"
self-imposed
is similar to
not brought about by coercion or force
"the confession was uncoerced"
uncoerced, unforced, willing
is similar to
without payment
"the soup kitchen was run primarily by unpaid helpers"; "a volunteer fire department"
unpaid, volunteer
see also
knowing and perceiving; having awareness of surroundings and sensations and thoughts
"remained conscious during the operation"; "conscious of his faults"; "became conscious that he was being followed"
conscious
see also
resulting from one's intentions
"your intended trip abroad"; "an intended insult"
intended
see also
disposed or inclined toward
"a willing participant"; "willing helpers"
willing
controlled by individual volition
"voluntary motions"; "voluntary muscles"
voluntary
antonym
involuntary
domain category
the branch of the biological sciences dealing with the functioning of organisms
physiology