noun

the power of acting without the constraint of necessity or fate; the ability to act at one’s own discretion.

volition,independence,self-determination,self-sufficiency,autonomy,spontaneity,freedom,liberty,voluntarily,willingly,readily,freely,spontaneously,without reluctance,without being forced,without being asked,without being encouraged,of one’s own accord,of one’s own volition,of one’s own choosing,by one’s own preference

adjective

(especially of a donation) voluntary.

free-will offerings