volunteer
UK /ˌvɒl.ənˈtɪər/ US /ˌvɑː.lənˈtɪr/
A person who does something, especially helping other people, willingly and without being forced or paid to do it:
UK /ˌvɒl.ənˈtɪər/ US /ˌvɑː.lənˈtɪr/
A person who does something, especially helping other people, willingly and without being forced or paid to do it: