Behalf Be*half", n. [OE. on-behalve in the name of, bihalven by the side of, fr. AS. healf half, also side, part: akin to G. halb half, halber on account of. See Be-, and Half, n.] Advantage; favor; stead; benefit; interest; profit; support; defense; vindication. In behalf of his mistress's beauty. --Sir P. Sidney. Against whom he had contracted some prejudice in behalf of his nation. --Clarendon. In behalf of, in the interest of. On behalf of, on account of; on the part of.