The Sun divinatory meanings
Quite simply, the Sun indicates wealth, success, and happiness in the family. Look to the surrounding cards for where that wealth and success might come from. When weak, the Sun indicates the reversal of fortunes and problems in the family.
Book of Thoth
Give forth thy light to all without doubt; the clouds and shadows are no matter for thee.
Make Speech and Silence, Energy and Stillness, twin forms of thy play.
Glory, gain, riches, triumph, pleasure, frankness, truth, shamelessness, arrogance, vanity, manifestation, recovery from sickness, but sometimes sudden death.
The meanings for the Sun are fairly simple and consistent. Note that even when reversed, there is only a diminution of the interpretation, not necessarily the reverse.