browband

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.

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.

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 ...

Of course it was nothing to compare with the authentic crown, with its inlays and chasings of seven different precious metals, its finials of rare gems, its three gleaming diniaba-stones mounted on the browband.