a·cre-foot (??k?r-fo?ot?)n. The volume of water, 43,560 cubic feet, that will cover an area of one acre to a depth of one foot.American Heritage® Dictionary of the English Language, Fifth Edition. Copyright © 2016 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.acre-foot n, pl -feet (Units) the volume of water that would cover an area of 1 acre to a depth of 1 foot: equivalent to 43 560 cubic feet or 1233.5 cubic metresCollins English Dictionary ? Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014a?cre-foot? n. a unit of volume of water in irrigation: the amount covering one acre to a depth of one foot, equal to 43,560 cubic feet (1233 cubic meters). [1900?05, Amer.] Random House Kernerman Webster’s College Dictionary, © 2010 K Dictionaries Ltd. Copyright 2005, 1997, 1991 by Random House, Inc. All rights reserved.