C2 adjective /ˌsuː.pər.ɪˈrɑː.ɡə.tɔːr.i/
supererogatory
überflüssig
Meaning
Going beyond what is required or expected; more than necessary.
Example
His donation was supererogatory, far beyond what anyone had asked for.
Seine Spende war überflüssig, weit mehr, als jemand erwartet hatte.