"'Avers,' bestiaux qui nantissent une ferme à la campagne."
See also Jamieson (Scottish Dictionary):
"Aver, a cart-horse."
A suggestion may also be gathered from Webster under Average.
F. S. Q.
In the Chronicle of Jocelyn de Brakelond, at p. 29. of Tomlins's translation, mention is made of one Beodric,
"Lord of that town, whose demesne lands are now in the demesne of the Cellarer. And that which is now called Averland was the land of the rustics."
Again, at p. 30.:
The Cellarer was used freely to take all the dung-hills in every street, for his own use, unless it were before the doors of those who were holding averland; for to them only was it allowable to collect dung and to keep it."
To this a note is appended to the effect that