noun (n)

• United States liquid unit equal to 4 quarts or 3.785 liters(noun.quantity)

  Synonym:
  gal
  

  source: wordnet30
• a British imperial capacity measure (liquid or dry) equal to 4 quarts or 4.545 liters(noun.quantity)

  Synonym:
  congius, imperial gallon
  

  source: wordnet30
• A measure of capacity, containing four quarts; -- used, for the most part, in liquid measure, but sometimes in dry measure.(noun)

  source: webster1913