tabard
/ˈtæbəd/noun
1- a sleeveless jerkin consisting only of front and back pieces with a hole for the head无袖套头衫。
1.1
- historical a coarse garment of this kind as the outer dress of medieval peasants and clerics, or worn as a surcoat over armour〈史〉（中世纪农民和牧师穿的）粗布外衣; （盔甲外的）披风。
1.2
- a herald's official coat emblazoned with the arms of the sovereign（饰有王徽的）传令官无袖制服。
词源
Middle English: from Old French tabart, of unknown origin.