Definition of "aker"

… crope of an aker might have been worth=3 p aker ...

1858, Jonathan Brown Bright, The Brights of Suffolk‎, Digitized edition, published 2006, page 127

That all rates that shall arise upon the Towne shall be layed upon Lands accordinge to every ones p'portion aker for aker of howse lotts and aker for aker of meddowe both alike on this side and both alike on the other side …

1859, New England Historic Genealogical Society, The New England Historical & Genealogical Register‎, Digitized edition, S.G. Drake, published 2009, page 295