The definition of behalf means in place of or for someone or something.(noun)
An example of behalf is a lawyer acting for her client.
See behalf in Webster's New World College Dictionary
Origin: ME, in phrase on (mi) behalfe, on (my) side < OE be, by + healf, half, side
See behalf in American Heritage Dictionary 4
Origin: Middle English
Origin: , from Old English be healfe, by (his) side
Origin: : be, by, at; see by1
Origin: + healf, side, half; see half. Usage Note: A traditional rule holds that in behalf of and on behalf of have distinct meanings. In behalf of means “for the benefit of,” as in We raised money in behalf of the earthquake victims. On behalf of means “as the agent of, on the part of,” as in The guardian signed the contract on behalf of the minor child. The two meanings are quite close, however, and the phrases are often used interchangeably, even by reputable writers.
Learn more about behalf