gallon Gallomaniac • gallonage · · · Info · Definitions · Synonyms · Characters · · gallon · · Text Latin · · Script 6 · · Length Definitions · · · (noun) United States liquid unit equal to 4 quarts or 3.785 liters. Synonyms: gal. · · Noun Definition 1 (noun) a British imperial capacity measure (liquid or dry) equal to 4 quarts or 4.545 liters. Synonyms: Imperial gallon, congius. · · Noun Definition 2 Synonyms · · · gal · · Synonym 1 imperial gallon · · Synonym 2 congius · · Synonym 3 Characters · · a latin small letter a U+0061 g latin small letter g U+0067 l latin small letter l U+006C n latin small letter n U+006E o latin small letter o U+006F