term:

Voluntary

voluntary adj

1 a : proceeding from one's own free choice or consent rather than as the result of duress, coercion, or deception [a statement]
b : not compelled by law
: done as a matter of choice or agreement [ arbitration]
c : made freely and with an understanding of the consequences [a plea of guilty]
2 : done by design or intention
3 : made without valuable consideration or for nominal consideration [a conveyance]
vol·un·tar·i·ly [vÄ -lən-ter-ə-lē]
adv

vol·un·tar·i·ness n

Source: Merriam-Webster's Dictionary of Law ©1996. Merriam-Webster, Incorporated. Published under license with Merriam-Webster, Incorporated.