voluntaryvol·un·ta·ry /ˈvɒləntəriˈvɑːlənteri/ adjectiveadj1done or agreed to willingly and without being forcedHe suggested that workers take voluntary pay cuts to help the economy.
Cigar advertising on television is banned under a voluntary agreement.
The company was wound up on a voluntary basis.
2voluntary work/service etc work etc that is done by people who do it because they want to and are not paid, or are paid very littleIn her spare time, Elaine does voluntary work for a mental health charity.