An Etymological Dictionary of Astronomy and Astrophysics

1. In a cathode-ray tube, the glow surrounding a bright spot that appears on the fluorescent screen as the result of the screen’s light being reflected by the front and rear surfaces of the tube’s face.
   

2. The effect in which a halo appears around the image of a bright object recorded on a photographic film or plate. It is produced by the fan-like pattern of light reflected through the emulsion by the medium’s backing material.

Etymology (EN): Halation, from hal(o), → halo + -ation a combination of -ate and -ion, used to form nouns from stems in -ate.

Etymology (PE): Hâlegiri, from hâlé, → halo + giri, verbal noun of gereftan “to take, seize” (Mid.Pers. griftan, Av./O.Pers. grab- “to take, seize,” cf.
Skt. grah-, grabh- “to seize, take,” graha “seizing, holding, perceiving,” M.L.G. grabben “to grab,” from P.Gmc. *grab, E. grab “to take or grasp suddenly;” PIE base *ghrebh- “to seize”).