The Collaborative International Dictionary of English v.0.48:

Parhelion \Par*hel"ion\, n.; pl. Parhelia. [L. parelion, Gr.
   ?, ?; para` beside + ? the sun.]
   A mock sun appearing in the form of a bright light, sometimes
   near the sun, and tinged with colors like the rainbow, and
   sometimes opposite to the sun. The latter is usually called
   an anthelion. Often several mock suns appear at the same
   time. Cf. Paraselene.
   [1913 Webster]

WordNet (r) 3.0 (2006):

parhelion
    n 1: a bright spot on the parhelic circle; caused by diffraction
         by ice crystals; "two or more parhelia are usually seen at
         once" [syn: parhelion, mock sun, sundog]