(archaic) a battle helmet used by soldiers in ancient times

(literary) soldier or troops, by extension from the word for helmet; notably used in the poem 南乡子·登京口北固亭有怀 nán​xiāng​zǐ​dēng​jīng​kǒu​běi​gù​tíng​yǒu​huái by 辛弃疾 xīn​qì​jí