BEHALF

[be.half] n [ME, fr. by + half half, side] (14c): interest, benefit; also: support, defense "argued in his ~" -- on behalf of or in behalf of : in the interest of; also: as a representative of usage A body of opinion favors in with the "interest, benefit" sense of behalf and on with the "support, defense" sense. This distinction has been observed by some writers but overall has never had a sound basis in actual usage. In current British use, on behalf (of) has replaced in behalf (of); both are still used in American English, but the distinction is frequently not observed.