blackacre

[blak-ey-ker]

noun (often initial capital letter)

an arbitrary name for a piece of land used for purposes of supposition in legal argument or the like (often distinguished from whiteacre).

Origin of blackacre

First recorded in 1620–30; black + acre

Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018

Suppose I am to buy Blackacre, and employ attorney Blackstone to search the title.
Commercial Law
Samuel Williston, Richard D. Currier, and Richard W. Hill
I am sorry you cannot get your money; continue to tell us all your perplexities, and do not mind being called Widow Blackacre.
Mary Lamb
Anne Burrows Gilchrist