volunteer

/ˌvɒlənˈtɪər/ verb [I or T]

Definition

› to offer to do something without being paid for it or without being asked to do it: If they're short of helpers, I could volunteer.volunteer to do sth I volunteered to do the accounting.volunteer for sth He volunteered for early retirement.volunteer sb for/to do sth He volunteered his wife for the job. More residents need to step forward and volunteer time and energy.

(Definition of volunteer verb from the Cambridge Business English Dictionary © Cambridge University Press)