a person who voluntarily offers himself or herself for a service or undertaking.
2.
a person who performs a service willingly and without pay.
3.
Military. a person who enters the service voluntarily rather than through conscription or draft, especially for special or temporary service rather than as a member of the regular or permanent army.
4.
Law.
a.
a person whose actions are not founded on any legal obligation so to act.
b.
a person who intrudes into a matter that does not concern him or her, as a person who pays the debt of another where he or she is neither legally nor morally bound to do so and has no interest to protect in making the payment.
a. a person who performs or offers to perform voluntary service
b. (as modifier): a volunteer system; volunteer advice
2.
a person who freely undertakes military service, esp temporary or special service
3.
law
a. a person who does some act or enters into a transaction without being under any legal obligation to do so and without being promised any remuneration for his services
b. property law a person to whom property is transferred without his giving any valuable consideration in return, as a legatee under a will
4.
a. a plant that grows from seed that has not been deliberately sown
b. (as modifier): a volunteer plant
—vb
5.
to offer (oneself or one's services) for an undertaking by choice and without request or obligation
6.
(tr) to perform, give, or communicate voluntarily: to volunteer help; to volunteer a speech
7.
(intr) to enlist voluntarily for military service
[C17: from French volontaire, from Latin voluntārius willing; see voluntary]
c.1600, "one who offers himself for military service," from M.Fr. voluntaire, noun use of adj. meaning "voluntary," from L. voluntarius "voluntary, of one's free will" (see voluntary). Non-military sense is first recorded 1638. The verb is first recorded 1755, from the