<p><strong>Noun</strong></p><ul><li>A person who voluntarily offers to perform a service or other undertaking.</li><li>A person who performs a service willingly and without pay.</li><li>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.</li><li>Law: a person whose actions are not founded on any legal obligation to act.</li><li>A person who steps into a matter that does not concern them, such as a person who pays the debt of another where they are neither legally nor morally bound to do so and has no interest to protect in making the payment.</li><li>Agriculture: also volunteer plant, a plant that springs up spontaneously, without being seeded, planted, or cultivated by a person.</li><li>A native or inhabitant of Tennessee (used as a nickname).</li></ul><p><strong>Adjective</strong></p><ul><li>Of, relating to, or being a person who voluntarily offers to do something: a volunteer fireman.</li><li>Agriculture: growing without being seeded, planted, or cultivated by a person; springing up spontaneously: volunteer tomatoes.</li></ul><p><strong>Verb (used without object)</strong></p><ul><li>To offer oneself for some service or undertaking.</li><li>To enter service or enlist voluntarily.</li></ul><p><strong>Verb (used with object)</strong></p><ul><li>To offer (oneself or one's services) for some undertaking or purpose.</li><li>To give, bestow, or perform voluntarily: to volunteer a song.</li><li>To say, tell, or communicate voluntarily: to volunteer an explanation.</li><li>To promise the services of (someone) without having asked if it is something they actually can or want to do: He volunteered me to sand and paint the bottom of the boat, and I don’t have the slightest interest in sanding, painting, or boating.</li></ul>