Upright
The equal but opposite counterbalance to the Magician. Confident. Compassionate. Eminently feminine. Mysterious. Private. Secretive. Intuitive. Moody and aloof. Knowing all, but expressing her secrets by measure, or through symbolism. Yet a powerful advisor. A well of knowledge, but only a cup at a time is dispensed. Surprising and unexpected revelations may by coming. The High Priestess may often represent the subject, if female, or the object of the subject's desire, if male. Also, perhaps a suggestion for introspection or meditation. Traditionally, she represents knowledge kept secret, modesty, discretion.
Reversed
Passion. Indiscretion. Immodesty. Promiscuity. Seduction. Betrayal. Revealing secrets to cause embarassment and hurt, rather than to share knowledge. Selfishness or shallowness. The High Priestess reversed may also be a warning to pay heed to feminine health issues.
Correspondences
Element: Water
Zodiac: The Moon