Emily Dickinson Lexicon

BROW, n. [Sax. bræw, bruwa; D. braauw; G. braue; Russ. brov; Ir. bra, brai, eyebrow, and abhra, the eyelid; Sans. bruwan, bru; Gr. οφρυη, οφρυς; Pers. بُرُو or اَبْرُو, bro or abro; and the last syllable of L. palpebra. It is probably contracted from brg, and signifies an edge, border or projection.]

1. The prominent ridge over the eye, forming an arch above the orbit. The skin of this arch or ridge is moved by muscles, which contract it in a frown and elevate it in joy or surprise. Hence, to knit the brows, is to frown. – Encyc.
2. The hair that covers the brow forming an arch, called the eye brow.
3. The forehead. Hence, the general air of the countenance. – Shak. Waller.
4. The edge of a steep place, as the brink of a river or precipice; as, the brow of a hill. – Bacon.
5. A fringe of coppice, adjoining to the hedge of a field. – Mason.