Definition of on behalf of someone
1
: as a representative of someone
- The teacher accepted the award on behalf of the whole class.
2
or US
in behalf of someone
or
in someone's behalf
: for the benefit of someone : in support of someone
- She spoke in behalf of the other candidate.
- They're willing to do anything on their child's behalf.
3
: because of someone
- Don't get up on my behalf.
