noun
acre
AY-kur/ˈeɪkər/
A unit of land area equal to 43,560 square feet.
The marked parcel covers one acre.

Etymology
Originally a field without a fixed size, an acre became the amount of land a team of oxen could plow in a day. It was later standardized as a precise unit of area.
In context
the XIT a three million acre ranch just think about that for a minute