1. adherence to moral and ethical principles; soundness of moral character; honesty.
2. the state of being whole, entire, or undiminished: to preserve the integrity of the empire.
3. a sound, unimpaired, or perfect condition: the integrity of a ship’s hull.
1. rectitude, probity, virtue. See honor.
My personal twist on the definition? When your behavior matches your philosophy. Antonym? Hypocrisy.