What does "voluntary" mean?

Additional senses

1. 2.Done by design or intention; intentional; purposed; intended; not accidental; as, if a man kills another by lopping a tree, it is not voluntary manslaughter.
2. 3.(Physiol.) Of or pertaining to the will; subject to, or regulated by, the will; as, the voluntary motions of an animal, such as the movements of the leg or arm (in distinction from involuntary motions, such as the movements of the heart); the voluntary muscle fibers, which are the agents in voluntary motion.
3. 4.Endowed with the power of willing; as, man is a voluntary agent. God did not work as a necessary, but a voluntary, agent, intending beforehand, and decreeing with himself, that which did outwardly proceed from him. Hooker.
4. 5.(Law) Free; without compulsion; according to the will, consent, or agreement, of a party; without consideration; gratuitous; without valuable consideration.
5. 6.(Eccl.) Of or pertaining to voluntaryism; as, a voluntary church, in distinction from an established or state church. Voluntary affidavit or oath (Law), an affidavit or oath made in extrajudicial matter. -- Voluntary conveyance (Law), a conveyance without valuable consideration. -- Voluntary escape (Law), the escape of a prisoner by the express consent of the sheriff. -- Voluntary jurisdiction. (Eng. Eccl. Law) See Contentious jurisdiction, under Contentious. -- Voluntary waste. (Law) See Waste, n., 4.
6. 7.One who engages in any affair of his own free will; a volunteer. [R.] Shak.
7. 8.(Mus.) A piece played by a musician, often extemporarily, according to his fancy; specifically, an organ solo played before, during, or after divine service.
8. 9.(Eccl.) One who advocates voluntaryism.