Unpaid
Part of speech: adjective
Definition: Not paid for.
Example sentence: I suspect the real reason the N.F.L. and N.B.A. don't want high schoolers and college underclassmen to play with their ball is that they don't want to jeopardize their relationship with National Collegiate Athletic Association, which serves as a sort of free minor league and unpaid promotional department for the pros.
Volunteer
Part of speech: noun
Definition: One who enters into, or offers for, any service of his own free will, especially when done without pay.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.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.A person who acts out of his own will without a legal obligation, such as a donor.A plant that grows in disturbed soil.A native or resident of the American state of Tennessee.
Part of speech: verb
Definition: To enlist oneself as a volunteer.To do or offer to do something voluntarily.To grow without human sowing or intentional cultivation.
Example sentence: This is pure speculation, but for a period of time, a lot of getting into a party was through fundraising and volunteer work, and Republican women had more time to do that than democratic women, who were out there getting jobs.