An Etymological Dictionary of Astronomy and Astrophysics

1. A very harsh, bright, dazzling light.
   

2. A type of → light pollution which is
   a blinding light within the field of vision. It compromises security and safety.

Etymology (EN): M.E. glaren; cognate with M.Du., M.L.G. glaren; akin to glass.

Etymology (PE): Xirtâv, literally “dazzling light,” from xir, from xiré konandé, “dazzling,” from xiré “much, many; obstinate; perverse; unwilling;” + tâv, variant tâb, tâbidan “to shine,” → luminous.