Synonyms of 'advance guard'

airhead, avant-garde, battle line, beachhead, bridgehead, cordon, cordon sanitaire, forefront, front, front line, Garrison, goalie, goalkeeper, goaltender, guard, guardsman, innovation, jailer, line, new look, novelty, outguard, outpost, picket, pioneer, point, precursor, railhead, rear guard, scout, spearhead, Van, vanguard, warder