Defeasance

n.	1.	A defeat; an overthrow. After his foes' defeasance. - Spenser.
	2.	A rendering null or void.
	3.	(Law) A condition, relating to a deed, which being performed, the deed is defeated or rendered void; or a collateral deed, made at the same time with a feoffment, or other conveyance, containing conditions, on the performance of which the estate then created may be defeated.

DEFEASANCE, contracts, conveyancing. An instrument which defeats the force or operation of some other deed or estate. That, which in the same deed is called a condition, in another deed is a defeasance.
     2. Every defeasance must contain proper words, as that the thing shall be void. 2 Salk. 575 Willes, 108; and vide Carth. 64. A defeasance must be made in eodem modo, and by, matter as high as the thing to be defeated; so that if one be by deed) the other must also be by deed. Touchs. 397.
     3. It is a general rule, that the defeasance shall be a part, of the same transaction with the conveyance; though the defeasance may be dated after the deed. 12 Mass. R. 13 Pie P. 413 1 N. 11. Rep. 41; but see 4 Yerg. 57, contra. Vide Bouv. Inst. Index, h.t.; Vin. Ab. h.t.; Com. Dig. h.t.; Id. Pleader, 2 W 35, 2 W 37; Lilly's Reg. h.t.; Nels. Ab. h.t.; 2 Saund. 47 n, note 1; Cruise, Dig. tit. 32, c. 7,, s. 25; 18 John. R. 45; 9 Wend. R. 538; 2 Mass. R. 493.