havelock

名词 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.（名词）
A cloth covering for a cap, having a flap to cover and protect the back of the neck.
遮颈布：军帽的一块有垂布遮盖和保护脖子后部的遮布

来源：
After Sir Henry Havelock (795-857), British soldier
源自亨利 哈弗洛克 爵士(795-857年），英国士兵