An Etymological Dictionary of the German Language/Braue
Braue, f., ‘eyebrow,’ from the equiv. MidHG. brâ, brâwe, OHG. brâwa, f.; a pre-Teut. and more remotely old Aryan word, which was perhaps *brêwa in Goth. The OGall. and Kelt. brîva, identical with this word, signifies ‘bridge,’ and is especially important as proving the connection between these cognates and those of Brücke. OHG. brâwa (Aryan bhrêwâ) is related by gradation to Aryan bhrû, which is proved by AS. brû, E. brow, OSlov. brŭvĭ, Sans. bhrû, Gr. ὀ-φρύς. Comp. further OIc. brá, OLG. brâha (for brâwa), AS. brœ̂w, m., and also perhaps Lat. frons, ‘forehead.’ A widely diffused Aryan root. The ModHG. Braune has added to the stem the suffix n, which belonged to the declension of the weak form Braue (comp. Biene); similarly OIc. brún, corresponding to AS. brû, was formed from brû and the n of the weak declension (in AS. the gen. plur. is brûna}. Braue, like the names of many limbs and parts of the body (see Fuß, Niere, Herz, Leber, Nase), originated in the primit. Aryan period. The orig. meaning, however, of the primit. Aryan bhrû-s (‘eye)-brow,’ is as difficult to discover as that of Herz. See also Brücke