Quote from American Heritage Dictionary:

"The state of being unimpaired. Purity. Uprightness."

Description:

INTEGRITY is the keeper of the gates leading between worlds, the ruler of souls. On his staff of power he holds the three-tiered pyramid, symbol of the body, mind and spirit. He wears the open, triple crown of initiation, leaving his upper chakra bared. He is the one who makes holy things appear; he is the interpreter of principles. On his chest he wears the split halves of the cycle of energy, tied together yet forever separated into action and reaction. He is in control of the emotional nature, shown by the quiet stream separating him from those who ask entrance into higher consciousness.

Interpreted use:

When this trump is drawn, use the moment to cross the stream by asking the right question, which must secretly come from within yourself alone.

Reversed (card received upside down):

Unless you behave with INTEGRITY, you won't cross the stream. It takes more than kneeling to get across.