noun.
In horticulture, a plant that comes up of itself from naturally scattered seed, in distinction from one that comes from sowing by the horticulturist.
To offer, contribute, or bestow voluntarily, or without constraint or compulsion.
To enter into any service of one's free will, without constraint or compulsion: as, to volunteer for a campaign
noun.
A person who enters into any service of his own free will.
noun.
A person who enters military service of his own free will, and not by constraint or compulsion; one who offers to serve, and generally receives some consideration or privileges on that account; in the United States, especially during the civil war, a soldier of a body other than the regular army, but practically governed by the same laws when in service.
noun.
In law, one who claims the benefit of a contract or conveyance although no consideration proceeded from him nor from any one in whose place he stands.
noun.
A tree which grows spontaneously: as, that pear-tree in my garden is a volunteer.
Entering into military service by free will and choice: as, a volunteer soldier.
Composed of volunteers: as, a volunteer corps.