behalf

behalf
noun
(用于短语 on 美亦作 in behalf of 或 on someone's/something's behalf)

in the interests of a person, group, or principle
为了（个人或团体）的利益，为了维护（某个原则）
he campaigned on behalf of the wrongly convicted four.
他为那四个受到错判的人奔走呼吁。
as a representative of
代表
he had to attend the funeral on Mama's behalf.
他只好代表妈妈参加丧礼。

语源

Middle English : from a mixture of the earlier phrases on his halve and bihalve him, both meaning 'on his side' (see by, half)