from
The Collaborative International Dictionary of English v.0.48
Gainage \Gain"age\ (?, 48), n. [OF. gaignage pasturage, crop, F.
gaignage pasturage. See {Gain}, v. t.] (O. Eng. Law)
(a) The horses, oxen, plows, wains or wagons and implements
for carrying on tillage.
(b) The profit made by tillage; also, the land itself.
--Bouvier.
[1913 Webster]
from
Bouvier's Law Dictionary, Revised 6th Ed (1856)
GAINAGE, old Eng. law. It signifies the draft oxen, horses, wain, plough,
and furniture for carrying on the work of tillage by the baser sort of @soke
men and villeins, and sometimes the land itself, or the profits raised by
cultivating it. Bract. lib. 1, c. 9.