brow表示“眉,眉毛”,是可数名词,但常用复数。brow还可表示“斜坡的上部”,常接of。

He had a feverish brow.他的额头发热。
Her arched brows are like a quarter moon and very pretty.她眉弯如月,非常好看。
We reached the brow of the hill.我们到达山脊上。

［词源］＜中古英语brow(睫毛,眼睑)