The American Heritage® Dictionary of the English Language, 4th Edition
n. Any of various French units of land measurement, especially one used in parts of Canada and the southern United States and equal to about 0.4 hectare (0.85 acre).
n. A unit of length, having various official measures
n. A unit of area, having various official measures
the GNU version of the Collaborative International Dictionary of English
n. Formerly, a measure of land in France, varying in different parts of the country. The arpent of Paris was 4,088 sq. yards, or nearly five sixths of an English acre. The woodland arpent was about 1 acre, 1 rood, 1 perch, English.
The Century Dictionary and Cyclopedia
n. An old French measure for land.
WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
n. a former French unit of area; equal approximately to an acre
Word Usage
"The arpent is the old French measure that is approximately one acre in size."