volunteer

American Heritage® Dictionary of the English Language, Fourth Edition

1. n. A person who performs or offers to perform a service voluntarily: an information booth staffed by volunteers; hospital volunteers.
2. n. Law A person who renders aid, performs a service, or assumes an obligation voluntarily.
3. n. Law A person who holds property under a deed made without consideration.
4. n. Botany A cultivated plant growing from self-sown or accidentally dropped seed.
5. adj. Being, consisting of, or done by volunteers: volunteer firefighters; volunteer tutoring.
6. adj. Botany Growing from self-sown or accidentally dropped seed. Used of a cultivated plant or crop.
7. v. To give or offer to give voluntarily: volunteered their services; volunteer to give blood.
8. v. To perform or offer to perform a service of one's own free will.
9. v. To do charitable or helpful work without pay: Many retirees volunteer in community service and day care centers.

Century Dictionary and Cyclopedia

1. n. In horticulture, a plant that comes up of itself from naturally scattered seed, in distinction from one that comes from sowing by the horticulturist.
2. n. A person who enters into any service of his own free will.
3. n. 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. In Great Britain the government provides the various bodies of volunteers, or citizen-soldiery, with competent instructors, arms, and a part of their ammunition, besides allowing to each corps certain grants proportioned to the number of efficient members, etc. A British volunteer can resign on giving a fortnight's notice, except in a crisis of imminent danger to the country. In the United States the army of volunteers comprises, to all intents and purposes— the regular unpaid forces of State militia which, when called into the actual service of the United States, receive pay from the government, and are subject to the rules and articles of war, and that class of troops which may from time to time be raised by Congress on occasions of national emergency. Such troops are properly United States troops, and the method of officering them is designated by Congress.
4. n. 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.
5. n. A tree which grows spontaneously: as, that pear-tree in my garden is a volunteer.
6. Entering into military service by free will and choice: as, a volunteer soldier.
7. Composed of volunteers: as, a volunteer corps.
8. To offer, contribute, or bestow voluntarily, or without constraint or compulsion.
9. To enter into any service of one's free will, without constraint or compulsion: as, to volunteer for a campaign

Wiktionary

1. n. One who enters into, or offers for, any service of his/her own free will, especially when done without pay.
2. n. military One who enters into military service voluntarily, but who, when in service, is subject to discipline and regulations like other soldiers; -- opposed to conscript; specifically, a voluntary member of the organized militia of a country as distinguished from the standing army.
3. n. law A person who acts out of his own will without a legal obligation, such as a donor.
4. n. botany A plant that grows in disturbed soil.
5. n. A native or resident of the American state of Tennessee.
6. v. intransitive To enlist oneself as a volunteer.
7. v. transitive To do or offer to do something voluntarily.
8. v. intransitive, botany To grow without human sowing or intentional cultivation.

GNU Webster's 1913

1. n. One who enters into, or offers for, any service of his own free will.
2. n. (Mil.) One who enters into service voluntarily, but who, when in service, is subject to discipline and regulations like other soldiers; -- opposed to conscript; specifically, a voluntary member of the organized militia of a country as distinguished from the standing army.
3. n. (Law) A grantee in a voluntary conveyance; one to whom a conveyance is made without valuable consideration; a party, other than a wife or child of the grantor, to whom, or for whose benefit, a voluntary conveyance is made.
4. adj. Of or pertaining to a volunteer or volunteers; consisting of volunteers; voluntary.
5. v. To offer or bestow voluntarily, or without solicitation or compulsion.
6. v. To enter into, or offer for, any service of one's own free will, without solicitation or compulsion.

WordNet 3.0

1. n. a person who performs voluntary work
2. adj. without payment
3. v. tell voluntarily
4. n. (military) a person who freely enlists for service
5. v. agree freely
6. v. do volunteer work
7. n. a native or resident of Tennessee