Volunteer

1. a. Of or pertaining to a volunteer or volunteers; consisting of volunteers; voluntary; as, volunteer companies; volunteer advice.
2. a. One who enters into, or offers for, any service of his own free will.
3. a. 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.
4. a. 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.

The word meanings were obtained from OPTED(The Online Plain Text English Dictionary), which is based on “The Project Gutenberg Etext of Webster’s Unabridged Dictionary” which is in turn based on the 1913 US Webster’s Unabridged Dictionary (See Project Gutenburg), as a text file.