The American Heritage® Dictionary of the English Language: Fourth Edition. 2000.
Appendix I
Indo-European Roots
ENTRY:
bhr-
DEFINITION:
Eyebrow. Contracted from *bhru-.1.brow, from Old English br-, eyebrow, eyelid, eyelash, from Germanic *brs.2. Possibly in the sense of a beam of wood, and perhaps a log bridge. bridge1, from Old English brycg(e), bridge, from Germanic *brugj (with cognates in Celtic and Slavic). (Pokorny 1. bhr- 172, 2. bhr- 173.)