A clause in a deed which requires the grantee to return something to the grantor out of the property granted, such as royalties of minerals.

Reference Desk:

A Law Dictionary, Adapted to the Constitution and Laws of the United States. By John Bouvier. Published 1856.

REDDENDUM, contracts. A word used substantively, and is that clause in a deed by which the grantor reserves somethingnew to himself out of that which he granted before, and thus usually follows the tenendum, and is generally in these words“yielding and paying.”
     2. In every good reddendum or reservation, these things must concur; namely, 1. It must be apt words. 2, It must be ofsome other thing issuing or coming out of the thing granted, and not a part of the thing itself, nor of something issuing out ofanother thing. 3. It must be of such thing on which the grantor may resort to distrain 4. It must be made to one of thegrantors and not to a stranger to the deed. Vid 2 Bl. Com. 299; Co. Litt. 47; Touchs 80; Cruise, Dig. tit. 32, c. 24, s. 1; Dane’Ab. Index, h.t.

Black’s Law Dictionary, 2d edition (1910).

Lat In conveyancing. Rendering; yielding. The technical name of that clause in a conveyance by which the grantor creates or reserves some new tiling to himself, out of what he had before granted ; as “rendering therefor yearly the sum of ten shillings, or a pepper-corn,” etc. That clause in a lease in which a rent is reserved to the lessor, and which commences with the word “yielding.” 2 Bl. Comm. 299.

Wiktionary

n. A clause in a deed by which some new thing is reserved out of what had been granted before; the clause by which rent is reserved in a lease.

The Century Dictionary and Cyclopedia

n. In law, a reservation in a deed whereby the grantor creates or reserves some new thing to himself, out of what he had granted before.