voluntary


1 : done, given, or made with one's own free will <voluntary assistance>
2 : not accidental : INTENTIONAL <voluntary manslaughter>
3 : of, relating to, or controlled by the will <voluntary behavior>
synonyms VOLUNTARY, INTENTIONAL, DELIBERATE, WILLING mean done or brought about of one's own will. VOLUNTARY suggests free choice <joining the club is voluntary> or control by the will <voluntary blinking of the eyes>. INTENTIONAL suggests that something is done for a reason and only after some thought <intentional misbehavior>. DELIBERATE suggests that one is fully aware of what one is doing and of the likely results of the action <a deliberate insult>. WILLING suggests a readiness and eagerness to go along with the wishes of another <willing obedience>.

 http://www.wordcentral.com/cgi-bin/student book=Student&va=Voluntary

Giving up my allowance to help the homeless was voluntary – no one made me do it.