(of a person or action) acting or done willingly, without being forced
acting or done without payment; controlled or supported by people who give their money, services, etc., of their own free will
done on purpose
"man is a voluntary agent"
"participation was voluntary"
"voluntary generosity in times of disaster"
"voluntary social workers"
"a voluntary confession"
Were faith not voluntary, it could not be praised.
出自： J. Ruskin