the leaders of a movement in society, for example in politics, art, industry, etc. （政治、藝術、工業等社會活動的）領導者，先鋒，先驅者 the part of an army, etc. that is at the front when moving forward to attack the enemy 先頭部隊；前衛；尖兵 The army was advancing steadily and the vanguard was already at the border. 軍隊穩步前進，先頭部隊已經到達邊境。
Word Originlate Middle English (denoting the foremost part of an army): shortening of Old French avan(t)garde, from avant ‘before’ + garde ‘guard’.