Voluntary  —adj. 1 acting, done, or given willingly; not compulsory; intentional. 2 unpaid (voluntary work). 3 (of an institution) supported by charity. 4 (of a school) built by a charity but maintained by a local education authority. 5 brought about by voluntary action. 6 (of a movement, muscle, or limb) controlled by the will. —n. (pl. -ies) organ solo played before or after a church service.  voluntarily adv. Voluntariness n. [latin voluntas will]