gal·lon 
(gălən)
(gălən)n.
1. Abbr. gal.
a. A unit of volume in the US Customary System, used in liquid measure, equal to 4 quarts (3.785 liters).
b. A unit of volume in the British Imperial System, used in liquid and dry measure, equal to 4 quarts (4.546 liters). See Table at measurement.
2.
a. A container with a capacity of one gallon.
b. The contents of such a container.
[Middle English, a liquid measure, from Old North French galon.]