- a common unit of capacity in English-speaking countries, equal to four quarts, the U.S. standard gallon being equal to 231 cubic inches (3.7853 liters), and the British imperial gallon to 277.42 cubic inches (4.546 liters). Abbreviation: gal.
- Also called: imperial gallon British a unit of capacity equal to 277.42 cubic inches. 1 Brit gallon is equivalent to 1.20 US gallons or 4.55 litres
- US a unit of capacity equal to 231 cubic inches. 1 US gallon is equivalent to 0.83 imperial gallon or 3.79 litres
- (plural) great quantities
liquid measure, late 13c., from Old North French galon, corresponding to Old French jalon “liquid measure,” related to jale “bowl,” from Medieval Latin diminutive form galleta “bucket, pail,” also “a measure of wine,” of unknown origin, perhaps from Gaulish galla “vessel.”
- A unit of volume in the US Customary System, used in liquid measure, equal to 4 quarts, 231 cubic inches, or 8.3389 pounds of distilled water (3.7853 liters).
- A unit of liquid volume or capacity in the US Customary System equal to 4 quarts (3.79 liters). See Table at measurement.