The state of being one; oneness. Unity may consist of a simple substance or existing being, as the soul; but usually it consists in a close junction of particles or parts, constituting a body detached from other bodies. Unity is a thing undivided itself, but separate from ever other thing.

Concord; conjunction; as a unity of proofs.

Agreement; uniformity; as unity of doctrine; unity of worship in a church.

In christian theology, oneness of sentiment, affection or behavior. How good and how pleasant it is for brethren to dwell together in unity! Psalm 133:1.

In mathematics, the abstract expression for any unit whatsoever. The number 1 is unity, when it is not applied to any particular object; but a unit, when it is so applied.

In poetry, the principle by which a uniform tenor of story and propriety of representation is preserved. In the drama, there are three unities; the unity of action, that of time, and that of place. In the epic poem, the great and almost only unity is that of action.

In music, such a combination of parts as to constitute a whole, or a kind of symmetry of style and character.

In law, the properties of a joint estate are derived from its unity, which is fourfold; unity of interest, unity of title, unity of time, and unity of possession; in other words, joint-tenants have one and the same interest, accruing by one and the same conveyance, commencing at the same time, and held by one and the same undivided possession.

In law, unity of possession, is a joint possession of two rights by several titles, as when a man has a lease of land upon a certain rent, and afterwards buys the fee simple. This is a unity of possession, by which the lease is extinguished. Unity of faith, is an equal belief of the same truths of God, and possession of the grace of faith in like form and degree. Unity of spirit, is the oneness which subsists between Christ and his saints, by which the same spirit dwells in both, and both have the same disposition and aims; and it is the oneness of christians among themselves, united under the same head, having the same spirit dwelling in them, and possessing the same graces, faith, love, hope.