volunteer

volunteer (danh từ) nghĩa là tình nguyện viên, người tình nguyện, lính tình nguyện.

1. One who enters into, or offers themselves for, any service of their own free will, especially when done without pay.Người tự nguyện nhận làm một công việc, đặc biệt là không nhận thù lao.
2. One who enters into military service voluntarily (but who, when in service, is subject to discipline and regulations like other soldiers), as opposed to a conscript.Người tự nguyện nhập ngũ và phải tuân theo kỷ luật, quy định như các quân nhân khác.
3. A voluntary member of the organized militia of a country, as distinguished from a regular or member of the standing army.
4. A person who acts out of their own will without a legal obligation, such as a donor.
5. A plant that grows spontaneously, without being cultivated on purpose; see volunteer plant in Wikipedia.

• The volunteers at the nature reserve meet up ever other Sunday to help its upkeep.