imperial gallon

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun A unit of measure for liquids used in the British Isles and in some Commonwealth countries, equivalent to 8 imperial pints, 4.55 litres, or 1.20 U. S. gallons.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun a British imperial capacity measure (liquid or dry) equal to 4 quarts or 4.545 liters