Definitions
1.nounA unit of volume, equivalent to eight pints
2.nounExactly 4.54609 liters; an imperial gallon
3.noun231 cubic inches or approximately 3.785 liters for liquids (a "U.S. liquid gallon")
4.nounOne-eighth of a U.S. bushel or approximately 4.405 liters for dry goods (a "U.S. dry gallon").
5.noun(in the plural) A large quantity (of any liquid)."The pipe burst and gallons of water flooded into the kitchen."