Gallon

gallon. (gal'-en)

    1. In the United States, a liquid measure with a capacity of 231 cubic inches (3.7854 liters) equal to 128 fluid ounces. One U.S. gallon equals 5/6 of an imperial gallon. Abbrev: U.S. gal. 2. In the United Kingdom and the Commonwealth, the imperial gallon (or U.K. gallon) is a liquid measure of 277.42 cubic inches (4.5459 liters) (10 pounds avoirdupois of water at 17 °C), equal to 160 fluid ounces. It is the fundamental unit of capacity in the United Kingdom and is defined in the Weights and Measures Act 11 & 12 Eliz. II, 1963. The gallon is mentioned in Piers Plowman (1342) and was given legal status as a unit in 1602. The imperial gallon is somewhat larger than the U.S. Ggallon: 1 imperial gallon equals 1.20094 (6/5) U.S. gallons. Abbrev: imp. gal; U.K. gal.