Integrity, n.
Etymology: [L. integritas: cf. F. intégrité. See Integer, and cf. Entirety.]
1. The state or quality of being entire or complete; wholeness; entireness; unbroken state; as, the integrity of an empire or territory. Sir T. More.
2. Moral soundness; honesty; freedom from corrupting influence or motive; -- used especially with reference to the fulfillment of contracts, the discharge of agencies, trusts, and the like; uprightness; rectitude. The moral grandeur of independent integrity is the sublimest thing in nature. Buckminster. Their sober zeal, integrity. and worth. Cowper.
3. Unimpaired, unadulterated, or genuine state; entire correspondence with an original condition; purity. Language continued long in its purity and integrity. Sir M. Hale.
Syn. -- Honesty; uprightness; rectitude. See Probity.
Shades of meaning
Fernald has no entry of its own for integrity; he lists it under justice, virtue.
Where he writes about it:
Integrity, rectitude, right, righteousness and virtue denote conformity of personal conduct to the moral law, and thus necessarily include justice, which is giving others that which is their due. — from justice
Integrity, in the full sense, is moral wholeness without a flaw; when used, as it often is, of contracts and dealings, it has reference to inherent character and principle, and denotes much more than superficial or conventional honesty. — from virtue