a person who voluntarily offers himself or herself for a service or undertaking.
a person who performs a service willingly and without pay.
a person who enters the service voluntarily rather than through conscription or draft, esp. for special or temporary service rather than as a member of the regular or permanent army.
a person whose actions are not founded on any legal obligation so to act.
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 volunteer plant.
(cap.) a native or inhabitant of Tennessee (used as a nickname).
—adj.
of, pertaining to, or being a volunteer or volunteers: a volunteer fireman.
growing without being seeded, planted, or cultivated by a person; springing up spontaneously.
—v.i.
to offer oneself for some service or undertaking.
to enter service or enlist as a volunteer.
—v.t.
to offer (oneself or one's services) for some undertaking or purpose.
to give, bestow, or perform voluntarily: to volunteer a song.
to say, tell, or communicate voluntarily: to volunteer an explanation.