名詞 havelock:

1. a cloth covering for a service cap with a flap extending over the back of the neck to protect the neck from direct rays of the sun

have.lock

n.（名詞）
A cloth covering for a cap, having a flap to cover and protect the back of the neck.
遮頸布：軍帽的一塊有垂布遮蓋和保護(hù)脖子后部的遮布

來(lái)源：
After Sir Henry Havelock (795-857), British soldier
源自亨利 哈弗洛克 爵士(795-857年），英國(guó)士兵