brow

brow (n.) words for "eyelid," "eyelash," and "eyebrow" changed about maddeningly in Old and Middle English (and in all the West Germanic languages). Linguists have untangled the knot into two strands: 1. O.E. bræw (Anglian *brew) "eyelid," from P.Gmc. *bræwi- "blinker, twinkler" (related to Goth. brahw "twinkle, blink," in phrase in brahwa augins "in the twinkling of an eye"); the sense must have shifted before the earliest recorded O.E. usage from "eyelash" to "eyelid." 2. O.E. bru "eyelash," from P.Gmc. *brus "eyebrow," from PIE root *bhrus (Cf. Skt. bhrus "eyebrow," Gk. ophrys, O.C.S. bruvi, Lith. bruvis "brow," O.Ir. bru "edge"). The sense of this must have been transferred in Old English at an early date from "eyebrow" to "eyelash."

Lacking a distinctive word for it, the Anglo-Saxons called an eyebrow ofer-bru, and in early Middle English they were known as uvere breyhes or briges aboue þe eiges. By c.1200, everything had moved "up." Bru/brouw (from bræw) became "eyelid;" and brew/breow (from O.E. bru) became "eyebrow." It remained the word for "eyebrow" in Scottish and northern English, where it naturally evolved into colloquial bree.

In southern English, however, M.E. bru/brouw took over the sense of "eyebrows," in the form brues, and yielded the usual modern form of the word. To make matters worse, if possible, some southern writers 15c.-17c. used bree for "eyelashes," in what OED calls "a curious reversion to what had been the original OE. sense of bru." By 1530s, brow had been given an extended sense of "forehead," especially with reference to movements and expressions that showed emotion or attitude. The -n- in the Old Norse (brun) and German (braune) forms of the word are from a genitive plural inflection.