1. as the agent of or on someone's part (usually expressed as `on behalf of' rather than `in behalf of')

- the guardian signed the contract on behalf of the minor child

- this letter is written on behalf of my client

Definition categories: act, lieu, place, position, stead

2. for someone's benefit (usually expressed as `in behalf' rather than `on behalf' and usually with a possessive)

- in your behalf

- campaigning in his own behalf

- spoke a good word in his friend's behalf

Definition categories: attribute, interest, sake