Brent-hill
means the eyebrows.
Looking or gazing from under brenthill. In Devonshire means “frowning at one;” and in West Cornwall to brend means to wrinkle the brows. It is very remarkable that the word should have such opposite meanings.
· 
· 
Entry taken from Dictionary of Phrase and Fable, edited by the Rev. E. Cobham Brewer, LL.D. and revised in 1895.