browband

noun

1. Part of a horse's bridle that runs from just under one ear, across the forehead, to just under the other ear, preventing the bridle from sliding down.
2. A band of fur of a contrasting colour on an animal's brow.“Diana monkeys are generally black or dark grey, but have a white throat, crescent-shaped browband, ruff and beard.”
3. A band of metal, part of a (person's) helmet or crown, which covers the brow.“Helmet of Buggenum-Montefortino type, from Anatolia, end of the first century AD […] The browband — riveted to the dome on each side — was part of its reinforcing structure, protecting the legionary from direct blows ...”