D defs.my
Entry 1 sense Webster, 1913

Halation

/(hā̇*lā"shŭn)/ · Ha·la·tion · IPA /həˈleɪʃən/
01 n. An appearance as of a halo of light, surrounding the edges of dark objects in a photographic picture.
  1. 1.
    An appearance as of a halo of light, surrounding the edges of dark objects in a photographic picture.(Photog.)