Acre-foot Definition

ākər-fo͝ot

noun

The volume of water, 43,560 cubic feet, that will cover an area of one acre to a depth of one foot.

American Heritage

The quantity of irrigation water (43,560 cubic feet or c. 325,851 U.S. gallons) that would cover one acre to a depth of one foot.

Webster's New World

A unit of volume equal to an acre times a foot, about 1233.5 kiloliters, or 66 feet by 660 feet by 1 foot.

Wiktionary

(US, engineering, agriculture) A unit of measure, used for volumes of water, equal to one acre times one foot (that is, to the amount of water required to cover one acre of land to a depth of one foot), which is 43,560 cubic feet, 325,851 gallons, 1,233 cubic meters.

Wiktionary